JSS_0256-01

JSS 0256-01 : 1992 (Revision No. 1)

MINISTRY OF DEFENCE

JOINT SERVICES SPECIFICATION

ON

ENVIRONMENTAL TEST METHODS FOR MISSILE SYSTEM

JSS 0256-01 : 1992

MANAKIKARAN NIDESHALAYA RAKSHA UTPADAN TATHA POORTI VIBHAG RAKSHA MANTRALAYA, H-BLOCK, DHQ PO

NEW DELHI – 110 011

DIRECTORATE OF STANDARDISATION DEPARTMENT OF DEFENCE PRODUCTION & SUPPLIES

MINISTRY OF DEFENCE, H-BLOCK, DHQ PO NEW DELHI – 110 011

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JSS 0256-01 : 1992 (Revision No. 1)

RECORD OF AMENDMENTS

Amendment Amended by No. Date

Amendment pertains to : Sl. No. /Para No.

/ Column No.

Authority Name & Appointment

(In BLOCK LETTERS)

Signature & Date

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JSS 0256-01 : 1992 (Revision No. 1)

CONTENTS

PAGE NO.

FOREWORD 1

SECTION 1 : GENERAL INFORMATION

1. SCOPE 2

2. RELATED SPECIFICATION AND DOCUMENTS 3

3. DEFINITIONS 3

4. STANDARD ATMOSHPERIC CONDITIONS 5

SECTION 2 : GENERAL PRECAUTIONS IN TESTING

1. GENERAL 8

2. MODIFICATION TO TESTS 8

3. EQUIPMENT UNDER TEST 8

4. CONDITIONS AT START AND END OF THE TEST 8

5. TEST CHAMBERS 8

SECTION – 3 : GROUPING OF EQUIPMENT AND RECOMMENDED SEQUENCES OF TESTS

1. GENERAL 10 2. GROUPS 10 3. APPLICABLE TETS AND RECOMMENDED SEQUENCES FOR

VARIOUS GROUPS 12

SECTION –4 : DESCRIPTION OF TEST METHODS

1. TEST NO. 1 HIGH TEMPERATURE 14

2. TEST NO. 2 LOW TEMPERATURE 16

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JSS 0256-01 : 1992 (Revision No. 1)

3. TEST NO. -3 ALTITUDE 18

4. TEST NO. -4 TROPICAL EXPOSURE 23

5. TEST NO. –5 TEMPERATURE SHOCK 26

6. TEST NO. -6 SOLAR RADIATION 28

7. TEST NO. –7 DRIVING RAIN 30

8. TEST NO. –8 ICING 36

9. TEST NO. -9 DUST 38

10. TEST NO. –10 CORROSION (ACID) 43

11. TEST NO. –11 CORROSION (ALKALINE) 47

12. TEST NO. –12 CORRSION (SALT) 50

13. TEST NO. -13 MOULD GROWTH 54

14. TEST NO. -14 ACDUSTIC VIRBATION 59

15. TEST NO. -15 VIRBATION 70

16. TEST NO. –16 ACCELERATION (STEADY STATE) 103

17. TEST NO. –17 AERODYNAMIC HEATING 108

18. TEST NO. –18 SHOCK 111

19. TEST NO. -19 IMPACT 117

20. TEST NO. -20 DROP 119

21. TEST NO. –21 BUMP 121

22. TEST NO. –22 TOPPLING 126

23. TEST NO. –23 ROADABILITY TEST 128

24. TEST NO. –24 DROP TEST 132

25. TEST NO. –25 TRANSIT DROP TEST 134

26. TEST NO. –26 ELECTROSTATIC DISCHARGE (ESD) 137

SECTION – 5 : GUIDE LINES

1. INTRODUCTION 140

2. TAILORING PROCESS 140

3. LIFE CYCLE PROFILE 140

4. CRITERIA FOR INVOLVING ENVIRONMENTAL REQUIREMENT AND TEST PLANS

143

5. TESTING PHILOSOPHY 144

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JSS 0256-01 : 1992 (Revision No. 1) 0. FOREWARD 0.1 This specification has been prepared by Guided Missile Systems and Components Standardization Sub Committee , on the authority of Standardization committee ,ministry of defence .

0.2 This specification is approved by the ministry of Defence and is mandatory for use by the Defence Services . 0.3 This JSS would be used for design, manufacture, quality Assurance and procurement of the item . 0.4 This specification is revision of JSS 0256-01 :1985 and super shades the Same . 0.5 Quality Assurance Authority for the item covered by this JSS is CQAS,DQAN and DTD& P (Air) for Army , Navy and queries regarding this specification relating to any contractual conditions should be addressed to The Inspection Authority named in the tender or contract. Other technical enquiries should be referred to the Director , Directorate of Standardization, Ministry of Defence , New Delhi – 110011 . 0.6 Copies of this specification can be obtained on payment from : The Director Directorate of Standardization Ministry of defence NEW DELHI – 110 011. 0.7 This specification holds good only for the supply order for which it is issue

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JSS 0256-01 : 1992 (Revision No. 1)

SECTION – 1 : GENERAL INFORMATION

1. SCOPE 1.1 This specification describes standard procedures and conditions for environmental test for all equipment for services applications .The term ‘Equipment for the purpose of this specification’, shall mean Missile and Missile borne systems . It dose not apply to support equipment.

1.2 This Specification includes environmental conditions obtainable in the laboratory, such that if an item is exposed to these conditions and continuous to operate in a satisfactory manner , a high degree of confidence will have been established that the item could survive the field environment during its expected operational and storage life . The tests described herein are not to be interpreted an exact and conclusive representation of actual operational and storage conditions. It is also the purpose of this document to standardize environmentalists in order to obtain, as much as possible ,reproducible test results .

1.3 The tests specified herein are intended to serve the need for predetermining the potential cause of failure of equipment under operational and storage environments. In some of the tests, the test conditions are varied in order to enable the designers select the conditions which will be adequate to meet the users (qualitative)requirements , commensurate with the design efforts.

1.4 The acceptable performance limits of the equipment when subjected to environmental tests are not included in this specification. The relevant equipment specification shall define the acceptable performance limits during and after the specified environmental tests. 1.5 The relevant equipment specification, which is the governing document for production and supply of the equipment for the users, shall always invoke the tests and conditions laid down in this specification, to provide a common basis for comparison for performance of various equipment.

1.6 THIS SPECIFICATION , IN ITSELF , DOSE NOT CONSTITUTE AN INSTRUCTION TO APPLY THE TESTS . Such instructions, together with the incidence and grouping of equipments for tests for the purposes of design approval and the acceptance (inspection ) shall be specified in the relevant equipment specification . While conducting any test described in Section 4 of this specification, standard procedures and conditions of tests shall be followed (see 1.9). 1.7 In section 4 and elsewhere terms “specified” “unless otherwise specified”, “as required”, “if required”, and “when required” have been used. In such cases the details shall be as given in the relevant equipment specification. 1.8 The tests included in this specification do not cover all operational and storage environments and additional tests, where necessary, may need to be specified in the relevant equipment specification. 1.9 The relevant equipment specification shall specify the deviations in test procedure which may be necessary when applying the tests and also any special procedures which may be required.

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JSS 0256-01 : 1992 (Revision No. 1) 2. RELATED SPECIFICATION AND DOCUMENTS

2.1 Joint services Specifications

JSS 55 555 1988 (R)

Environmental Test Methods for Electronic and Electrical Equipment.

JSG –0102 1984 Environmental Testing of Armament and Packages.

JSG – 0270 1987 EMI / EMC Specification for Missile System

3. DEFINITIONS

The following definitions shall apply : -

3.1 Ambient Temperature.

3.1.1 For Non-Heat Dissipating Equipment – The temperature of the medium surrounding the equipment. 3.1.2 For Heat Dissipating Equipment – Where the conditions are those of ideal cooling by convection, the temperature of the medium at such a distance from the equipment that the effect of dissipation is negligible. NOTE 1 : In practice it is taken as the average of temperatures measured at a number of points in a horizontal plane through a point 0 mm to 50 between the equipment and the wall of the tes chamber or at 1 m distance, whichever is less. NOTE 2 : IF forced circulation is used in the testing of heat dissipating equipment, the concept of ambient temperature is no longer valid. Under these conditions, the testing should be based these conditions, the testing should be based on the specification of the surface temperature or the requirements of the relevant equipment. 3.2 Conditioning – The exposure of an equipment to an environmental condition in order to determine the effect or such a condition on it.

3.3 Final Measurements – The measurements made at the conclusion of a test so that a comparison with the initial measurement will show the effect of the test on the equipment . NOTE : Final measurements made at the end of test may be taken as the initial measurements of the subsequent test . 3.4 Heat Dissipating Equipment – For the purpose of environmental testing ,an equipment is

considered heat dissipating when the hottest point on its surface , measured in free air conditions , is more than 5 deg above the ambient temperature of the surrounding atmosphere after temperature stability has been reached .

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JSS 0256-01 : 1992 (Revision No. 1)

NOTE : Measurements required to prove that an equipment can be regarded as non- heat dissipating , can be made in normal laboratory conditions , if care has been taken that no outside influence (for example , draughts or sunlight affects the measurements . it may be necessary to make measurement s at several points ) exists .

3.5 Initial Measurements – The measurements made prior to a test to determine the characteristics of the equipment . 3.6 Performance Check – Tests specified in the relevant specification, in order to check the performance of an equipment during the conditioning or immediately after it .

3.7 Preconditioning – The treatment of an equipment with the object of removing or partly counteracting the effects of its previous history. Where called for ,it is the first process in the test procedure .

3.8 Recovery – The treatment of an equipment , after conditioning , in order that the characteristics of the equipment may be stabilized before final measurements

3.9 Relevant Equipment Specification – A document specially drawn up or provided which lays down the characteristics and performance capabilities of an equipments under specified conditions of operation and storage as required by the services .

3.10 Temperature Stability – temperature stability has been reached when the temperature of all parts of the equipments are within 3 deg c , or other wise specified , of their final temperature. 3.10.1 For non – heat dissipating , the final temperature will be mean (in time)temperature of the chamber in which the equipment is placed . For heat dissipating equipment it is necessary to make repeated measurements to ascertain in interval of time required for the temperature to change3 deg c or as otherwise specified. Temperature stability has been reached when the ratio between consecutive intervals exceeds 1.7 .

NOTE 1 : where the thermal time constant of the equipment is short compared with the

duration of the exposure to a given temperature , no measurement is needed .

NOTE 2 : Where the thermal time constant of the equipment is of the same order as the duration of the exposure ,checks should be made to ascertain;A a) The non – heat dissipating equipments are within the required limit from the mean(in time) temperature of the atmosphere in which the equipment is placed .

(b) That for dissipating equipment the ratio between two consecutive time intervals exceeds 1.7 when repeated measurements are made to ascertain the interval of time required for the temperature to change by 3 deg c or as specified .

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JSS 0256-01 : 1992 (Revision No. 1)

NOTE : In practice , it may not be possible to make direct measurements of the internal temperature of the equipment . A check may then made by measuring some other parameter which is temperature dependent and for which the law of temperature dependent is known .

3.11 Test – A complete series of operational covered under a test heading. 3.12 Test Chamber - An enclosure in which the equipment can be exposed to the specified

environmental test conditions . 3.13 Test procedure – A complete series of operations covered by any one heading and shall normally consist of the following :

a) Preconditioning (where required) . b) Initial measurements (where required) . c) Conditioning , including performance check (hen specified) .

d) Recovery . e) Final measurements.

3.14 Visual examination – Visual examination is generally made before and after the conditioning in each test and from a part of Initial and final Measurements .During the visual examination of the equipment, defects in construction, the presence of foreign bodies, moisture, dust ,etc . corrosion of metal parts and from of deterioration of materials and finishes , distortion or mechanical imperfections shall be noted . 3.15 Working Space – That part of the test Chamber in which the specified environmental test conditions can be maintained within the specified tolerances .

4. STANDARD ATMOSPHERIC CONDITIONS

4.1 Standard Reference Conditions – If the para to be measured depend on temperature , and / or air pressure and if the law of dependence is known , the values are measured at conditions specified under 4.3 and , if necessary , corrected by calculation to the following reference values :

Temperature 20ºc

Air pressure 101.3 kPa

NOTE : No requirement for relative humidity is given because its correction by calculation is generally not possible .

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JSS 0256-01 : 1992 (Revision No. 1) 4.2 Standard Reference Conditions – If the parameter to be measured depend on temperature and / or air pressure and if the law of dependence is not known, measurements shall be made under the following reference conditions :

Temperature 20º c + 3 deg c .

Relative humidity 65 to 75 percent

Air pressure 86 to 106 kPa .

NOTE : In the case of large equipments or test chambers where temperature and

relative humidity and /or air pressure limits specified above are difficult to maintain , wider tolerances may be permissible . In such cases , the actual values used shall be given in the test report .

4.3 Standard testing Conditions – Measurements and mechanical checks may be carried out at any combination of temperature , relative humidity and air pressure , within the following limits :

Temperature 15 º c to 35 º c.

Relative humidity 45 to 75 per cent .

Air pressure 86 to 106 kPa

NOTE 1 : The temperature range may be extended beyond these limits , up to 10 º c

to 40º c for large equipment . NOTE 2 : The limits of variation of temperature and relative humidity carried during a

series of measurements carried out as part of one test on any equipment shall , if necessary , be specified in the relevant equipment specification .

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JSS 0256-01 : 1992 (Revision No. 1)

4.3.1 Where it is impracticable to carry out measurements within the limits of the standard atmospheric conditions for testing , a note to this effect, stating the actual conditions of tests shall be added to the test reports.

4.4 Standard Recovery Conditions – The standard conditions for recovery shall be actual laboratory conditions subject to the over –riding requirements of 4.3.

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JSS 0256-01 : 1992 (Revision No. 1)

SECTION 2 : GENERAL PRECAUTIONS IN TESTING

1. GENERAL

1.1 This section covers certain general precaution which the test engineers and personnel are required to observe .

2. MODIFICATION TO TESTS

2.1 In certain cases, there may be very good reasons for departing from the standard test methods , given in Section 4 . It is , therefore , essential to refer ,before caring out a test , to the relevant equipment specification , to ascertain , if any modifications , have been in the test conditions .

3. EQUIPMENT UNDER TESTS

3.1 Carriers , Covers , etc . and complete equipment should be tested with the appropriate carriers, covers shock and vibration mounts etc . ,which would befitted to the equipment under normal service conditions , unless otherwise specified by the relevant equipment specification.

3.2 Equipment of large Size – when the physical size of an equipment would prohibit its being tested as a complete unit , it may be broken down into sections of the largest possible size which can be accommodated satisfactorily (see 5.1)in the test equipment available . while doing so ,attention should be paid to the thermal geometry consideration of the equipment , if any , and if so specified in the relevant equipment specification .

4. CONDITIONS AT START AND END OF THE TEST

4.1 The equipment shall be introduced into or removed from the test chamber at the laboratory atmospheric conditions unless otherwise specified by the relevant equipment specification . While conducting the low air pressure test , the temperature of the chamber shall be stabilized at the specified temperature before reducing / increasing the air pressure .

5. TEST CHAMBERS

5.1 Volume of Test Chamber - The volume of the teat chamber test shall not interfere with the control and maintenance of test conditions in the working space of the chamber and any (--------) dissipated from the equipment under test shall not appreciably influence the conditions in the chamber . For this purpose , the volume of the test chamber should preferably be not less than eight times the volume of the equipment under test .

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JSS 0256-01 : 1992 (Revision No. 1) 5.2 Control of Temperature and relative Humidity – Wet and dry bulb thermo of mercury in glass type or thermocouples or equivalent sensors shall be used to control or determine the specified chamber temperature and relative humidity . These sensors shall be centrally located within the test chamber, where possible , or in the return air – stream and shall be baffled or otherwise protected against direct impingement of supply air and against direct impingement of supply air and against radiation effects. 5.3 Rate of Change of Temperature - Unless otherwise specified , the rate of change of temperature within the test chamber shall not exceed 1 deg c per minute , averaged over a period of not more than 5 minutes .

5.4 Uniformity of Conditions in Test Chamber – Necessary measures shall be taken to ensure that conditions throughout the chamber are homogeneous and are as near as possible to those prevailing in the immediate vicinity of the temperature and relative humidity sensors . The high / low temperature conditions inside the chamber should , therefore be , achieved only by circulating hot/ cold air . The air in the chamber shall be continuously agitated but not so vigorously as to cause undue cooling of the equipment under test . 5.5 Heat source for test Chamber - The heat source for test chamber shall be so located that the radiant heat dose not fall directly on the equipment under test except where radiant heat is one of the test conditions .

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JSS 0256-01 : 1992 (Revision No. 1)

SECTION – 3:

GROUPING OF EQUIPMENT AND RECOMMENDED SEQUENCES OF TEST

1. GENERAL

1.1 Ideally , equipment should be suitable for use in all conditions but this is not possible in practice because of high cost of design and production and in some cases , because of increased size . Most of the equipments have restricted sphere of use which , by limiting the severity conditions of use , may aloe simplification of the design with the restaurant reduction in cost .

1.2 Missile have a wide spectrum of operations . The severity under various conditions largely depend on their deployment conditions, role for which it is designed , the location of the equipment in the missile , and factors like permissible modes of transportation .Conventional classification based on range , role etc . , do not classify missiles into distinctive groups for which only a definite set of environmental tests are applicable . For example a short range missile like anti call for high altitude test ,if permitted to be airlifted . this test could be apparently dispensed with if airlift is permitted only under conditions where cargo compartment is pressurized . this may be too restrictive . Even if this is acceptable , the very fact that this restriction will call for altitude testing as well as temperature shock tests (Rapid temperature cycling ) as these effects will be encountered in case of transportable equipments /subassemblies . possibly these test for Missile can be skipped if the transportation is stipulated to be carried out only in sealed containers . Even then it will be desirable that the containers with missiles in positions are tested for the altitude and rapid temperature cycling . This leads on to the conclusion that it is but only proper to list all the r=tests covering the possible environmental conditions the missiles are likely to encounter . Applicability for a particular equipment is to be decided by the designer in consultation with users and inspection Authority taking all relevant factors into account . Guidance for selection of levels will be given appropriately in this document for selection.

2. GROUPS

2.1 Group : the categories of equipment are grouped as following : -

Group I Missiles frame , propulsion , liquid systems Hydraulic systems ,gas systems and mechanical equipment having only mechanical Equipment having only mechanical operating parts .

Group II Electrical Equipment other than Electronic Systems ,

Electrical power plants

Group III War head and pyro devices

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JSS 0256-01 : 1992 (Revision No. 1)

Group IV Control Equipments , Sensors , guidance equipment including accessories but not electronic ,optical and electro optical instruments .

Group V Electronic equipments

Group VI Complete missile .

2.2 Many of the equipment will in their normal storage and operations will be hermetically sealed and pressurized with dry air and other inert gases . if so , the testing of these equipment will be carried out in the same condition for the test to be meaningful.

3. Tests required for each group and recommended sequence of tests are given in table 3.1 . 3.1 The relevant equipment specification should choose only those tests out of the table, which are

considered applicable for the equipment under test. If required the recommended sequence may be changed for a particular equipment depending on the conditions of the use and/ or storage.

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JSS 0256-01 : 1992 (Revision No. 1)

APPLICABLE TESTS AND RECOMMENDED SEQUENCE FOR VARIOUS GROUPS

Test Sequence group wise :

Test No.

Tests I II III

IV V VI

1.

High Temperature 1 3 1 1 3 -

2.

Low Temperature 2 1 - 2 1 -

3.

Altitude 3 2 6 4 2 -

4. Tropical Exposure (Note 3)

6 6 2 3 13 -

5.

Temperature shock 4 4 - 5 12 -

6.

Solar radiation - - - 6 - 2

7. Driving Rain (Note 1)

5 7 3 - - 3

8.

Icing (Note 1) 7 8 - - - 4

9.

Dust 12 5 - - - -

10. Corrosion(Acid) (Note 1,2,3)

9 9 - 7 14 -

11. Corrosion (Alkaline ) (Note 1,2,3)

10 10 - 8 15 -

12. Corrosion (Salt) (Note 1,2,3)

11 11 4 9 16 -

13. Mould Growth (Note 2&3)

8 12 5 10 17 -

14.

Acoustic Vibration 20 20 - 18 11 7

15.

Vibration 19 19 9 17 10 6

16. Acceleration (Steady State)

13 13 12 16 4 5

17.

Aero Dynamic heating

- - - - - 1

18.

Shock (Note 1) 14 14 10 15 15 -

19.

Impact (Note 1) 15 15 11 12 7 -

20.

Drop (Note 1) 16 16 7 13 8 -

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JSS 0256-01 : 1992 (Revision No. 1)

21.

Bump(Note 1) 17 17 8 14 9 -

22.

Toppling(Note 1) 18 18 - 11 5 1

23.

Roadability Test - - - - - 10

24.

Transportation Test - - - - - 9

25.

Transit Drop Test - - - - - 8

Note 1 : Depending on the operational / storage conditions encountered this test may be chosen or omitted by relevant equipment specification .

Note 2 : For sealed equipment this test may be applied only to components and

finishes located outside the seal . Note 3 : Separate equipment can be used for this test . Note 4 : Combination of above tests may be resorted to by the designer , if required .

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JSS 0256-01 : 1992 (Revision No. 1)

SECTION - 4: DESCRIPTION OF TEST METHODS

TEST NO. 1

HIGH TEMPERATURE

1. OBJECT 1.1 To determine the resistant of equipment to high temperature that may be encountered in

service life either in storage or use . 2. TEST CHAMBER 2.1 A dry heat chamber meeting the requirements stated in 2.2 to 2.7 shall be used for this test

. 2.2 The chamber shall be capable of maintaining its working space at the appropriate high

temperature severity , within the following tolerances :

a) + 3 deg c for temperatures less than 100 º c . b) + 5 deg c for temperatures equal to or greater than 100 º c .

2.3 The relative humidity shall not exceed 50 percent . 2.4 The high temperature conditions in the chambers shall be achieved by circulating hot air

and these conditions shall be maintained uniformly , throughout the working space of the chamber .

2.5 The heating element s of the chamber shall be baffled to prevent direct radiation on the

equipment under test .

2.6 The temperature within the chamber shall be monitored by a temperature sensing device suitably located in its working space .

2.7 The design and construction of the chamber shall be such that any heat dissipated by the

equipment during testing shall not appreciably influence the conditions within the chamber .

3. TEST PROCIDURE 3.1 Initial Measurements – The equipments shall be such that any heat dissipated by the

equipment during testing shall not be subjected to electrical , mechanical and other checks , as specified .

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JSS 0256-01 : 1992 (Revision No. 1)

3.2 Conditioning . 3.2.1 The equipment under test shall be subjected to this test in “un parked” conditions. At the

beginning of the test the equipment shall be in its “Switched off" conditions. 3.2.1.1 The equipment under test being under laboratory atmospheric conditions shall be

introduced in the chamber, the latter also being under the same conditions. The chamber temperature shall then be raised to 55 º c . + 3 º c

3.2.1.2 The equipment shall then be exposed to this temperature for a period of 6 hours. The

temperature of chamber shall then be raised to 65 º c . + 3º c .and maintained for 4 hours . After this period , the chamber temperature will be brought back to 55 º c . + 3 º c . and maintained for further 6 hours .

3.2.1.3 If required the equipment shall be switched on and operated for a specified duration at any

ime during this period of exposure. Performance check shall be carried out at the end of each phase the maximum surface temperature attained by the component or materials in the equipment shall be measured and recorded, if required.

3.2.1.4 The temperature of the chamber shall then be restored to laboratory atmospheric

conditions. 3.3 Recovery – The equipment shall then be removed from the chamber and shall be allowed to

remain under standard recovery conditions.

3.4 Final measurements – The equipment shall then be visually examined and shall be subjected to electrical, mechanical and other checks, as specified.

4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT SPECIFICATIONS.

4.1 a) Initial Measurement (see 3.1) .

b) Duration of operation of equipment and the time at which this operation should commence

(see 3.2.1.3)

c) If measurement of surface temperature of equipment is required and if so the ocation (see 3.2.1.3).

4.2 Final measurements .(see 3.4 ).

4.3 Any deviation from the normal test procedure .

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JSS 0256-01 : 1992 (Revision No. 1)

TEST No . 2

LOW TEMPERATURE

1. OBJECT 1.1 The temperature suitability of the equipment for use /storage at specified low ambient

temperature conditions. 2. TEST CHAMBER 2.1 A cold chamber meeting the requirements stated in 2.2 to 2.5 shall be used for this test. 2.2 The chamber shall be capable of maintaining its working its working space within + 3

deg c of the appropriate low temperature severity .

2.3 The low temperature conditions in the chamber shall be achieved by circulating cold air and these conditions shall be maintained uniformly throughout the working space of the chamber

2.4 The temperature with in the chamber shall be monitored by a temperature sensing device

suitably located in its working spaces .

2.5 The design and construction of the chamber shall be such that any heat dissipated by the equipment during testing , shall not appreciably influence the conditions within the chamber .

3. TEST PROCIDURE 3.1 Initial Measurements - The equipments shall be visually examined and shall be subjected

to electrical , mechanical and other checks as specified . 3.2 Conditioning - The equipment under test shall be subjected to this test in “un packed

“conditions .at the beginning of the test the equipment shall be in its “switched off “ condition.

3.2.1 Procedure 3.2.1.1 The equipment under test while being in laboratory atmospheric conditions shall be

introduced into the chamber the latter also being under the same condition.

The chamber shall then be lower d to one of the test conditions given below :

a) - 40 º c . + 3º c .. b) –20 º c . + 3 º c ..

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JSS 0256-01 : 1992 (Revision No. 1)

3.2.1.2 After the equipment has attended temperature stability it will be maintained at proper test conditions for a period of 16 hours

3.2.1.3 If required , the equipment shall be switched on and operated for a specified duration at any

time during the test period . The performance check shall be carried out during the last 30 minute of the period specified .The chamber temperature shall be restored to test conditions after performance check .

3.2.1.4 At the completion of the test period , the equipment shall be subjected to recovery conditions

and final measurement shall be made as specified. 4. INFORMATION TO BE GIVEN IN THE RELAVANT EQUIPMENT

SPECIFICATION

4.1 Initial measurement (see 3.1 ). 4.2 a) Applicable test conditions . (see 3.2.1.1) .

b) The duration of operation of equipment and time at which this operation should be

commenced (see 3.2.1.4 ) . c) Performance check required during the test period .

4.3 Final measurement .(see 3.2.1.4) . 4.4 Any deviation from normal test procedure .

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 3

ALTITUDE

1. OBJECT

1.1 To determine the suitability of equipment for use and air transportation under simultaneously applied service conditions of low air pressure, high or low temperature and humidity.

2. TEST CHAMBER

2.1 An altitude chamber meeting requirements of 2.2 and 2.3 shall be used for this test . 2.2 The altitude chamber shall be capable of maintaining its working space at the appropriate

low air pressure severity within a tolerance of + 5 percent . In addition , the chamber shall also be capable of meeting all the requirements specified for test chamber for the high temperature test (Test Number 1)and the low temperature test (Test no 2) .

2.3 The altitude chamber shall also be capable of maintaining a relative humidity of not less than

95 percent as required for procedure 2. (see para 3.2.2) . .

3. TEST PROCIDURE

3.1 Initial measurements – The equipment under test shall be subjected to electrical , mechanical and other checks , specified .

3.2 Conditioning – The equipment under test shall be subjected to this test in ‘unpacked ‘

Condition . Two procedure are specified for this test . the equipment shall be subjected to one or of both these procedures as specified .

3.2.1 Procedure 1 –This shall be carried out in seven steps.

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TABLE 4.3- 1

TEST CONDITIONS FOR TEMPERATURE : ALTITUDE

Parameter step 1 2 3 4 5 6 7 Altitude 12000 m 0 H h H 0 A

M Temperature Ambient 40 º 40 T

h T H

T H

B I

Duration 1 hr - t 3 hrs 1 hr t E N T

TABLE 4.3-2

ALTITUDE TEMP . FOR CONDITIONS

Test condition Altitude M

0 C

A 1

5000 -15 º c

A 2

10000

-45 º c

A 3

20000

-55 º c

A 4

30000

-45 º c

H - Altitude ceiling for operation . h - Altitude ceiling for air transportation . t - Time required for carrying out performance check . T - Temp corresponding to height h . h

T - Temp corresponding to height H . H

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JSS 0256-01 : 1992 (Revision No. 1)

3.2.1.1 Step 1 - Adjust the chamber conditions as specified under Step 1 of table 4.3-1 . After test chamber conditions are stabilized , maintain these test conditions for one hour . At the end of this period , the test item shall to the extent possible , be visually inspected for presence of deterioration which would impair future operation .

3.2.1.2 Step 2 - Adjust the chamber test conditions to those specified in Step 2 of table 4.3-1 . 3.2.1.3 Step 3 - The chamber pressure shall be adjusted to the (-------) corresponding to one of the

test conditions A1 to A4 (Table 4.3 –2 )depending on operation . The performance check shall be carried out on the equipment as required .

3.2.1.4 Step 4 - Adjust the chamber pressure to one of the test conditions depending on altitude

ceiling for air transportation. Adjust the chamber temperature to the corresponding temperature given in Table 4.3.3 .Maintain the condition for 3 hours .

3.2.1.5 Step 5 – Adjust the chamber pressure corresponding to the one of the test conditions

depending on altitude ceiling for operation. Adjust the chamber temperature corresponding to the test conditions chosen as given in Table 4.3.2. Maintain the condition for 1 hour. The equipment shall then be operated as specified.

Note 1 : The equipment normally operated throughout the flight shall be operated from the start of the temperature conditioning and shall continue to operate throughout this step.

Note 2 : The equipment operated intermittently in flight shall be operated only when required conditioning has been done and equipment has achieved stable temperature.

3.2.1.6 Step 6 – Restore the chamber pressure to conditions specified in step 6 of Table 4.3.1.

Maintain the temperature corresponding to the test condition, depending on the altitude ceiling for operation. Carry out the performance check as specified.

3.2.1.7 Step 7 - Restore the chamber temperature to the laboratory atmospheric conditions and the

equipment shall be subjected to laboratory conditions. Carry out the performance check as specified.

3.2.2 Procedure 2.

3.2.2.1 The procedure shall immediately follow Procedure 1.

3.2.2.2 The chamber shall be lowered to –20° + 3°C and the chamber temperature allowed to

stabilize .

3.2.2.3 The air pressure inside the chamber shall then be reduced for a period of 30 minutes to a value corresponding to one of the test conditions given in Table 4.3.2 (depending on altitude ceiling for air transportation). The equipment shall then be operated as specified. It is usually continued for at least half an hour after equipment has commenced functioning or performance check is completed whichever is longer.

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JSS 0256-01 : 1992 (Revision No. 1)

Note 1 : The equipment normally operated throughout the flight shall be operated from the start of the temperature conditioning and shall continue to operate throughout this step.

Note 2 : The equipment operated intermittently in flight shall be operated only when required conditioning has been done and equipment has achieved stable temperature.

Note 3 : All measurements shall be made simultaneously at the end of warm up period where this is practicable, characteristics likely to be affected by low temperature should be checked.

3.2.2.4 The chamber temperature shall be raised to 40° C in a period of 1 to 2 hours with the relative

humidity held at close saturation (normally not less than 95%). Visible frosting should occur on the surface of the equipment when the mean temperature of the equipment has attained a level between 0°C and 50C and the frost has melted, air pressure in the chamber shall be restored to the laboratory conditions at approximately uniform rate during a period of 15 – 30 minutes.

Note : A saturated atmosphere conforming to these requirements shall be accepted without humidity measurements, if heating is by steam injection.

3.2.2.5 The equipment shall be operated and performance check shall be carried out as specified.

3.2.2.6 After the temperature and relative humidity have stabilized at 40°C and 95% respectively,

maintain the condition for one hour. During this period the equipment shall be operated and performance check carried out as specified.

3.2.2.7 Adjust the chamber conditions to –20°C ± 3°C and pressure corresponding to chosen test

conditions to altitude ceiling for air (Refer Para 3.2.2.3). This shall constitute one cycle.

3.2.2.8 Unless otherwise specified the equipment shall be subjected to 4 such cycles. At the end of last cycle, atmospheric conditions and the equipment shall be subjected to recovery conditions.

3.3 Recovery - The equipment shall then be removed from the chamber and shall be allowed to

remain in standard conditions for a period for 2 to 4 hours.

3.4 Final Measurement - The equipment shall then be visually examined and shall be subjected to electrical, mechanical and other checks as specified.

Note : In case of Procedure 2, the equipment shall be completely stripped

and examined for ingress of moisture if so required.

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JSS 0256-01 : 1992 (Revision No. 1)

4. INFORMATIONTO BE GIVEN IN THE RELEVANT EQUIPOMENT SPECIFICATION

4.1 Initial measurement (see 3.1)

4.2 Applicable Test Procedure (see 3.2)

4.3 Applicable test conditions depending on altitude ceiling for operation (Refer Table 4.3.2).

4.4 Applicable test conditions depending on altitude ceiling for operation (Refer Table 4.3.2).

4.5 a) Details of performance check.

b) Details and period of operation.

4.6 Level to which equipment is to be stripped for examination for ingress of moisture in case of Procedure 2. (see Note number 3.4).

4.7 Final Measurement (See 3.4)

4.8 Any deviation from normal test procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 4

TROPICAL EXPOSURE

1. OBJECT 1.1 To determine the suitability of equipment for use and storage conditions of high humidity

when combined with cycle temperature changes. 2. TEST CHAMBER

2.1 The damp heat chamber meeting the requirements of 2.2 to 2.10 shall be used for this test.

2.2 A damp heat chamber shall be capable of controlling and varying cyclically the temperature

of the working space between 20°C + 5° and 45°C + 2°C.

2.3 The chamber shall be capable of achieving in its working space, the rate of change of temperature as required in 3.2.2 and 3.2.5.

2.4 The chamber shall be capable of maintaining 95 percent relative humidity during the period

of high temperature and not less then 95 percent relative humidity during the rest of cycle.

2.5 Condensed water shall be continuously drained from the chamber and shall not be used again until it has been profiled.

2.6 When humidity conditions in the chamber are obtained by using dematerialized water, this

shall have a resistively of not less than 500 ohm metres.

2.7 Temperature and relative humidity of the chamber shall be monitored by sensing devices suitably located in the working space.

2.8 The condition prevailing throughout the working space shall be uniform and shall be as

similar as possible to those prevailing in the immediate vicinity of the sensing devices. Note : In case of damp heat chambers employing steam injection, the air velocity at the point accessibly to the wet bulb thermometer shall not be less than 3 m/s.

2.9 The properties of the equipment or its operation shall not appreciably influence the conditions within the working space of the chamber.

2.10 Any condensed water from the walls and roof the chamber shall not fall on the equipment.

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JSS 0256-01 : 1992 (Revision No. 1)

3. TEST PROCEDURE

3.1 Initial Measurements – The equipment shall be visually examined and shall be electrically and mechanically checked as specified.

3.2 Conditioning.

3.2.1 The equipment under test shall be subjected to this test. 3.2.2 The equipment under test while being under the laboratory atmospheric conditions shall be

introduced in to the chamber and maintained at temperature of 20°C + 5°C. 3.2.3 The temperature and R.H. of the chamber shall then be of raised to 45°C + 2°C and 95%

respectively over a period of 3 hours. 3.2.4 The above conditions shall be maintained for a period of 12 hours. 3.2.5 The temperature of the chamber shall then be lowered to 20°C + deg C over period of 3

hours. Saturation of the chamber atmosphere with water vapour shall occur during this period.

Note : Condensation may occur during the cooling period but water shall not drip on to

the equipment from the roof of the chamber. 3.2.6 The temperature of the chamber shall then be maintained at 20°C + 5°Cfor a period of 6

hours. 3.2.7 The above procedure from 3.2.2 to 3.2.6 constitutes one cycle refer Fig 4.4.1. The total

number of cycles shall correspond to one of the following test conditions, as required.

a) Test Condition A - 7 cycles b) Test Condition B – 14 cycles c) Test Condition C – 28 cycles d) Test Condition d – 56 cycles

Notes : The equipment shall be normally subjected to the test condition C. If required, the relevant equipment specification may extend the test duration to 56 Cycles, corresponding to test condition D, in case of fully exposed equipment. Test conditions A and B may be specified for protected and partially protected equipments.

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JSS 0256-01 : 1992 (Revision No. 1)

3.2.8 If required the equipment shall be switched on and operated during the first two hours of 45°C of each

3.2.9 In case of test conditions C or D, at completion of 14 cycles the equipment shall be examined

and performance checks shall be carried out as required.

3.3 Recovery – The equipment shall be removed from the chamber and shall be allowed to remain under standard recovery conditions for a period of 2 to 4 hours.

Note : The relevant equipment may specify method o removal of surface moisture.

3.4 Final Measurements – The equipment shall be visually examined and shall be electrically and

mechanically checked as specified.

4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT SPECIFICATION.

4.1 Initial Measurements (see 3.1)

4.2 Number of cycles (see 3.2.7). 4.3 Details of operation if required (see 3.2.8).

4.4 Final Measurement (see 3.4). 4.5 Any deviation from the normal test procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO.5 TEMPERATURE SHOCK

1. OBJECT 1.1 To determine the suitability of equipment to withstand rapid changes of temperature in air, as

may be encountered during use and air transportation. 2. TEST CHAMBER 2.1 The following chambers shall be sued, the location of chambers shall be as it allows a rapid

transfer of equipment from one chamber to the other. 2.1.1 A dry heat chamber conforming to the requirements of the high temperature test. 2.1.2 A cold chamber conforming to the requirements of the low temperature test number 2. 3. TEST PROCEDURE 3.1 Initial Measurement – The equipment shall be visually examined and shall be subjected to

electrical, mechanical and other checks as specified. 3.2 Conditioning - The equipment shall be subjected to this test, in its ‘unpacked’ and ‘switched-

off’ or ‘switched-on’ condition as specified. 3.2.1 Procedure. 3.2.1.1 The equipment, while being under laboratory atmospheric conditions, shall be introduced into

the dry heat chamber maintained at a temperature of 55°C + 3°C and relative humidity not exceeding 30 percent.

3.2.1.2 The equipment shall be maintained at this temperature for a period of 3 hours. The relative

humidity during this period shall not exceed 3 percent. 3.2.1.3 The equipment shall then be transferred to a cold chamber which is maintained at a

temperature depending on altitude ceiling on operation or air transportation, whichever is more severe (Refer Table 4.3.2 of Altitude Test).

3.2.1.4 The equipment shall be transferred from dry heat chamber to cold chamber as quickly as

possible. The time taken shall not exceed 6 minutes, unless otherwise specified.

3.2.1.5 The equipment shall be maintained at this temperature for a period of 3 hours. 3.2.1.6 The equipment shall then be transferred to the dry heat chamber at 55°C + 3°C and relative

humidity 30 percent. The time for transfer shall not exceed 6 minutes, unless otherwise specified.

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JSS 0256-01 : 1992 (Revision No. 1)

3.2.1.7 The equipment shall than be maintained at this temperature for three hours. 3.2.1.8 Conditioning stated in clause 3.2.1.3 to clause 3.2.1.7 shall constitute one cycle (refer Fig.

4.5.1). When relevant equipment specification requires conditioning for more than one cycle, the steps given in para 3.2.1.3 to 3.2.1.7 shall be repeated for stated number.

3.2.1.9 At the end of last cycle the equipment shall be removed from the cold chamber and shall be subjected to recovery conditions . (see 3.3 ) .

3.3 Recovery - The equipment shall be allowed to remain under the standard recovery

conditions for a period of 2 hours . 3.4 Final measurement - The equipment shall be visually examined and shall be subjected to

electrical , mechanical and other checks as specified .

4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT SPECIFICATION .

4.1 Initial measurements ( see 3.1 ) . 4.2 ‘Switched On ‘/ ‘ Switched Off ‘ condition (see 3.2 ) .

4.3 Transfer time (see 3.4 ). 4.4 Final measurements (see 3.4 ). 4.5 Any deviation from thee test procedure .

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO .6

SOLAR RADIATION

1. OBJECT

1.1 To determine the suitability of equipment normally exposed to solar radiation during service use .

2. TEST EQUIPMENT

2.1 A dry heat chamber conforming to requirements specified in high temperature test (test

number 1) shall be used . 2.2 The chamber shall be provided with means of obtaining simulate solar radiation of an

irradiance of 1.20 + 0.10 kw / m2. The simulated radiation shall have the following spectral distribution.

a) 540 to 775w/m2 of infra- red (radiation of wavelengths above 780 mm)

b) 40 to 75 w/m2 of ultra violet (radiation of wavelengths below 380mm) .

c) balance visible radiation .

Note :One of the following radiation sources may be used;

a) mercury vapour lamp (internal reflector type only b) combination of incandescent spot lamps(including infra- red filters )together with tabular

type mercury vapour lamps with external reflectors ( with filters as required ) .

c) combination of incandescent spot lamps(including infra- red filters )together with mercury vapour lamps with internal reflectors ( with filters required ) .

d) carbon arc lamps with suitable reflectors , or

e) mercury xenon arc lamps with suitable reflectors (with filters as required ).

3. TEST PROCIDURE

3.1 Initial measurements – The equipment shall be visually examined and shall be electrically

and mechanically checked as specified .

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JSS 0256-01 : 1992 (Revision No. 1)

3.2 Conditioning 3.2.1 The equipment shall be subjected to this test in the ‘unpacked ‘ and switched off conditions . 3.2.2 The equipment while being under the laboratory atmospheric condition , shall be introduced

into the chamber , the later also being under the same conditions . 3.2.3 The temperature of the chamber shall be adjusted to 30 º c + 3 º c and shall be maintained at

this temperature for a period of 9 hours. The relative humidity during this period shall not exceed 50 percent.

3.2.4 The temperature of the chamber shall then be raised to 550C+30C at an approximately linear

rate over a period of shours. During the last 3 hrs of this period, the radiant energy shall be increased unit only from zero level to the maximum (see 3.2).

3.2.5 The chamber shall be maintained at 55 º c + 3 º c for a period of 5 hours . The radiant energy

shall be maintained at a maximum level during this period . 3.2.6 The temperature of the chamber shall then be lowered to 30 º c + 3 º cat an approximately

linear rate over a period of 5 hours . During this period in the first 3hours the radiant energy level shall be uniformly reduced to zero .

Note :- The radiant energy during the conditioning specified in 3.2.4 to 3.2.6 should simulate the direct solar radiation in normal use .

3.2.7 Repeat Sep 3.2.4 to 3.2.6 four times . 3.3 Recovery – Thee equipment shall then be removed from the chamber and shall be allowed to

remain under standard recovery condition for a period of 2 to 4 hours . 4. INFORMATION TO BE GIEN IN THE RELEVANT EQUIPMENT

SPECIFICATION 4.1 Initial measurements (see 3.1). 4.2 Final measurements (see 3.4). 4.3 Any deviation from the normal test procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 7

DRIVING RAIN 1. OBJECT 1.1 To determine the suitability of equipment under conditions of rain . 2. TEST CHAMBER 2.1 A driving rain chamber meeting requirements of 2.2 to 2.4 shall be used for this test. 2.2 The driving rain chamber shall be capable of spraying water under laboratory atmospheric

conditions at a static pressure of 200 + 30 kpa percent from eight shower heads .

Note : The static pressure shall be measured nearest to each shower head .

2.3 It shall be possible to direct the spray from four of these shower heads downwards, at an angle of 45º, at each of the four upper most corners of the equipment under test and from the remaining four shower heads , horizontally at the center of the area of each of the four side of the equipment without excessive over leak from the adjacent shower heads at such a distance . that the intensity of water spray at the equipment under test shall be not less than the equivalent of the rainfall of 250 mm per hour .

2.4 The shower heads shall conform to fig . 4.7 –1. Use of such shower head will result in water

consumption of approximately 450 liters per hour at a static pressure of 200 kpa

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JSS 0256-01 : 1992 (Revision No. 1)

31

JSS 0256-01 : 1992 (Revision No. 1)

DIAGRAM

NOTE 1 : MATERIAL – BRASS NOTE 2 : DIMENSIONS ARE IN MILLIMETRES TOLERANCES + 0.15 NOTE 3: ALL BURRS TO BE REMOVED EXTERNAL EDGES TO BE RADIUSED OR

CHAMFERED 0.25 MIN INTERNAL CORNERS TO BE RADIUSED OR CHANFERED 0.5 MAX.

NOTE 4 : MACHINE SURFACE ROUGHNESS 32 UNLESS STAED OTHERWISE.

FIG . 4.7.2 SPRAY

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JSS 0256-01 : 1992 (Revision No. 1)

DIAGRAM

NOTE 1 : MATERIAL –BRASS NOTE 2 : DIMENSIONS ARE IN MILLIMETRES TOLERANCES + 0.15 UNLESS STATED

OTHERWISE NOTE 3 : ALL BURRS TO BE REMOVED EXTERNAL EDGES TO BE RADIUSED OR

CHAMFERED 0.25 MIN INTERNAL CORNERS TO BE READIUSED OR CHAMFERED 0.5 MAX.

NOTE 4 : MACHINE SURFACE ROUGHNEES 32 UNLESS STATED OTHERWISE.

FIG : 4.7.3 NUT

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JSS 0256-01 : 1992 (Revision No. 1)

3. TEST PROCIDURE 3.1 Initial measurements - The equipments shall be visually examined and shall be subjected to

electrical , mechanical and other checks as specified . 3.2 Conditioning –The equipment shall be subjected to this test, in its ‘unpacked

‘condition. It shall be kept in ‘switched off ‘ or’ switched on ‘conditions as specified. 3.2.1 The equipment under test , while being under the laboratory atmospheric conditions shall be

suitably positioned inside the chamber in its normal operational altitude as specified . 3.2.2 Tap water at laboratory temperature and at a static pressure of 200+ 30 kpa shall be spread

for 45 minutes or any other period as specified . The consumption of water from each shower head shall be 450 + 50 liters per hour .

3.2.3 Spray from the shower heads , shall be directed as : 3.2.3.1 Spray from four shower heads , directed at an angle of 45º c at each of the four uppermost

corner of the equipment for 15 minute 3.2.3.2 Spray from eight shower heads , four of them being directed at an angle of 45 On each of the

upper mo t corners of the equipment and the remaining four being directed horizontally at the center of the area of each of the four sides of the equipments for 15 minutes.

3.2.3.3 Repeat 3.2.3.1 for 15 minutes. 3.2.4 At the conclusion of the period specified in 3.2.2 the equipment shall be removed from this

chamber and ,if requires a performance check shall be carried out. 3.3 Recovery unless 0therwise specified, the external surface of the equipment shall be dried by

wiping or by applying a blast of air at room temperature . 3.4 Final Measurements - The equipment shall then be visually examined and shall be subjected

to electrical, mechanical and other checks as specified . 4. INFORMATION TO BE GIVEN IN RELEVANT EQUIPMENT

SPECIFICATION . 4.1 Initial Measurements (see 3.1) . 4.2 The equipment altitude (see 3.2.1).

4.3 Duration of exposure, if other than 45 minutes (see 3.2.2 )

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JSS 0256-01 : 1992 (Revision No. 1)

4.4 ‘Switched on’ or ‘ switched off ‘ condition ( see 3.2 ). 4.5 Details of performance check , if required ( see 3.2.4) .

4.6 Final measurement (see 3.4 ).


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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 8

ICING

1. OBJECT 1.1 To determine the effect of various icing conditions on the performance of equipment . 2. TEST CHAMBER 2.1 A chamber conforming to the requirements of low temp test (Test No .2 ) shall be used .

3. TEST PROCIDURE 3.1 Initial measurements - The equipments shall be visually examined electrically and/or

mechanically checked a required by the relevant equipment specification .

3.2 Conditioning - The equipment to be tested shall in all case , be in a condition representative of operational use . Un representative , coating and contaminants such as oils , grease and dirt , which could affect the adhesion between the ice and the surface of the equipments, shall be removed before commencing the test .

3.2.1 The operation of the equipment shall be checked at the most adverse phase of the test which

for most application would be a ‘switch on ‘ and brief functional checks under icing conditions . excessive operation of equipment which generates heat shall be avoided .

3.2.2 Procedure 3.2.2.1 The equipment shall be conditioned in a low temperature chamber as specified in low

temperature test until its temperature has stabilized at level determined by previous experiments, that will permit hard clear ice to form on the item when water is sprayed upon it. The optimum temperature is likely to be between - 1º c to –10 º c depending upon the thermal mass of the item .A homogeneous layer of hard clear ice (not white or air pocketed) shall be produced on the relevant surfaces of the equipment, to the required thickness and distribution by hand spraying / atomizer with a fine mist of water the temperature of which is close to freezing (say +2 º c).

3.2.2.2 When ice accretion has reached the level specified in the relevant equipment specification,

spraying shall be stopped and the performance check as specified carried out

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JSS 0256-01 : 1992 (Revision No. 1)

3.3 Recovery – The temperature of the chamber shall then be restored to the laboratory

atmospheric conditions . 3.4 Final measurements - The equipments shall be operated and a performance evaluation made

when the temperature and humidity have returned to standard laboratory conditions . 4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATIONS 4.1 Initial measurements (see 3.1). 4.2 Required thickness of ice (3.2.2.1)

4.3 Performance check (see 3.2.2.2 ).

4.4 Final measurements (see 3.4 ) .

4.5 Any deviation from the proposed procedure .

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 9

DUST 1. OBJECT 1.1 To determine the suitability of equipment for use and / or storage under dust laden

environment. 2. TEST CHAMBER 2.1 A dust chamber meeting requirement of 2.2 and 2.3 shall be used for this test . 2.2 The dust chamber shall be capable of circulating dust in its working space in such a manner

as to produce a dust concentration sufficient to deposit 25 + 5 grams of dust in the dust measuring device specified in 2.6.

Note : Fig 4.9 – 1 indicates suggested layout for this chamber .

2.3 The chamber shall also be capable of maintaining working space at a temperature of 40 º c +

3 º c with a relative humidity not exceeding 50 per cent. in all other respects , the chamber shall satisfy the requirements . Specified for the test chamber in high temperature test . (Test Number 1).

2.4 The dust used for this test shall be dry. It shall be heated to 40 º c + 3 ºc before the agitation

of the dust in the chamber is commenced. A sufficient quantity of dust shall be available in the chamber originally in order to give the specified dust concentration throughout the chamber.

2.5 The dust shall conform to the following requirements. 2.5.1 Physical characteristics

a) 100 percent dust shall pass through 100 mesh British Standard . b) 98 + 2 percent dust shall pass through 140 mesh British Standard .

c) 90 + 2percent dust shall pass through 200 mesh British Standard .

d) 75 + 2percent dust shall pass through 325 mesh British Standard .

2.5.2 Chemical composition – The chemical composition of the dust shall be as indicated in table 4. 9 – 1 .

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JSS 0256-01 : 1992 (Revision No. 1)

TABLE 4.9 – 1

CHEMICAL COMPOSITION OF DUST

SUBSTANCE PERCENTAGE BY WEIGHT

SiO 2

97 to 99

Fe O 2 3

0 to 2

Al O 2 3

0 to 1

TiO

0 to 2

MgO

0 to 1

Ignition

0 to 1

2.6 A dust measuring device is shown in Fig . 4.9-2 . The device shall be circulated for 5 minutes and the dust shall be allowed to settle down. The amount of dust collected in the device shall be 25 + 5 grams.

3. TEST PROCEDURE 3.1 Initial measurements – The equipments shall be visually examined and shall be electrically

and mechanically checked as specified. 3.2 Conditioning – The equipment shall be subjected to this test in its ‘unpacked ‘and ‘switched-

off ‘ conditions. 3.2.1 The equipment under test , while being under the laboratory atmospheric conditions shall be

introduced into the chamber , the latter also being under the same conditions . Sufficient quantity of dust shall also be introduced into the chamber.

3.2.2 The temperature of the chamber shall then be raised to a value of 40 ºc + 3 ºc. The relative

humidity shall be maintained at a value not exceeding 50 percent.

3.2.3 After temperature stability has been attained, the equipment shall then be subjected to a stream of dust laden air for a period of eight hours . During this period the dust concentration shall be maintained as in clause 2.2 .

3.2.4 If required, equipment shall then be discontinued and performance check shall be restored to

the laboratory atmospheric conditions.

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JSS 0256-01 : 1992 (Revision No. 1)

3.2.5 The circulation of dust shall then be discontinued and the temperature of the chamber shall be

restored to the laboratory atmospheric conditions.

3.3 Recovery – the equipment shall be removed from chamber and allowed to cool and any local accumulation of dust shall be noted . IF required the equipment shall then be electrically and mechanically checked.

3.4 Final measurements – The equipment shall be visually examined as specified and any local

accumulation f dust shall be noted. If required, the equipment shall then be electrically and mechanically checked .

Note – The accumulation dust shall be removed before electrical and mechanical checks

are made .The dust shall be removed by brushing , wiping or shaking . Under no circumstances shall the dust be removed by an air blast or vacuum cleaning.

4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATION. 4.1 Initial measurements (see 3.1 ). 4.2 Performance checks required (se 3.2.4 ).

4.3 Final Measurements (see 3.4) .

4.4 Any deviation from normal test procedure .

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JSS 0256-01 : 1992 (Revision No. 1)

41

JSS 0256-01 : 1992 (Revision No. 1)

FIG : 4.9.2 DUST MEASURING DEVICE

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 10

CORROSION (ACID)

1. OBJECT 1.1 To determine the suitability of equipment for use and for storage under the influence of

atmosphere containing sulphur dioxide . 2. TEST CHAMBER 2.1 An acid sprayed chamber meeting the requirements specified in clause 2.2 to 2.6 shall be

used for this test . Note : The chamber used for this test is similar in all respect to chambers specified

for procedure 1 in Test No . 12 Corrosion (Salt) . 2.2 The acid spray chamber shall be constructed from materials that will not affected adversely

by the corrosive influence of the sulphur dioxide solution used in the test . 2.3 The acid mist shall freely circulate aground the equipment under test . There shall be no

direct impingement of the acid mist on the equipment under test. The liquid which has come in contact with the equipment under test shall not be allowed to return to the reservoir containing the solution . Drops of liquid condensate accumulating on the walls , ceiling and other parts of the chamber shall not fall on the equipment under test.

2.4 The chamber shall be properly vented to prevent pressure build up inside the chamber.

2.5 The acid spray shall be produced by an automiser employing compressed air, which is free

from impurities.

2.6 It shall be possible to adjust the air pressure for spraying of the solution in the chamber such that the quantity of acid solution sprayed per hour shall be approximately one percent of the volume of the chamber.

2.7 The acid spray chamber or humidity chamber shall be used for storage of the equipments

under test for exposure to the conditions specified in clause 3.3.1.4 and 3.3.2.4 which ever chamber is used for this purpose , It shall be capable of maintaining its working space at a temperature of35 ºc + 2ºcand a relative humidity of 90 to 95 percent during the period s of storage of the equipment under test. The chamber used for this purpose shall satisfy the requirements specified for damp heat chamber in the tropical Exposure Test (Test no 4).

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JSS 0256-01 : 1992 (Revision No. 1)

3. TEST PROCIDURE 3.1 Initial measurements – The equipment shall visually examined and shall be subjected to

electrical, mechanical and other checks as specified. 3.2 Preparation of acid solution .

3.2.1 The acid solution to be sprayed shall consists of a solution of sulphur - dioxide in distilled

water . The composition of the solution shall be 0.3 percent (w/v)sulphur dioxide in distilled water . The solution shall be prepared as per clause 3.2.2 to 3.2.3.

3.2.2 A small quantity of distilled water at ambient temperature shall be saturated with

sculpture dioxide (use of fume cup board is desirable ) . This takes about half an hour. Towards the end of this period the temperature of the solution shall be raised to 36 ºc . This will yield a stock solution containing apprroximatly6 percent (w/v) sulphur dioxide in distilled water the stock solution shall be kept in a well stopped dark , bottle in a cool place and used within 28 days. Radially available sulphure dioxide solution of required concentration may also be used .

3.2.3 The test solution shall be prepared by dilution of 5mlstock solution with 95 ml o distilled

water it shall be kept in a well stoppered bottle in a cool place and used withn7 days.

Caution - sulphur dioxide and solutions of sulphur dioxide are harmful to human being and clothing. Operator carrying out this test must take precautions. They should not enter the chamber during spraying and the chamber should be purged with clean air to lower the concentration of sulphur dioxide in the air of the chamber to a safe level before it is entered after spraying. Rubber gloves should be used to handle equipment. If necessary a suitable respirator should be worn.

3.3 Conditioning – The equipment under test shall be subjected to this test in its ‘ un packed ‘and

switched off” condition two procedure are specified for this test the equipment shall be subjected to one of these procedure as specified.

3.3.1 Procedure 1 3.3.1.1 The equipment under test, while being at the laboratory atmospheric conditions , shall be

introduced into the acid spray chamber , the latter also being under the same conditions . 3.3.1.2 The equipment shall then be exposed to the acid mist, with the spray operating for a period of

2 hours under the laboratory atmospheric conditions. 3.3.1.3 The quantity of solution sprayed per hour shall be approximately one percent of the volume

of the chamber. 3.3.1.4 The equipment shall then be stored at a temperature of 35 ºc + 2 ºc and a relative humidity of

90 to 95 percent for a period of 7 days.

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JSS 0256-01 : 1992 (Revision No. 1)

3.3.1.5 The procedure specified in clause 3.3.1.2 to 3.3.1.4 constitutes one cycle. The equipment shall be subjected to a total of four consecutive cycles as above.

3.3.1.6 The equipment shall then be removed from the chamber and shall be examined for corrosion

and deterioration of metal parts , finishes , materials , components and contact materials . For non hermetically sealed items , the equipments shall be disassembled and examined for effects of acid corrosion.

3.3.2 Procedure 2

3.3.2.1 The equipment under test , while being under laboratory atmospheric conditions , shall be introduced into the acid spray chamber ,the latter also being under the same conditions .

3.3.2.2 The equipment shall then be exposed to the acid mist with the spray operating for a period

of 2 hours under the laboratory atmospheric conditions . 3.3.2.3 The quantity of solution sprayed per hour shall be approximately one percent of the chamber

3.3.2.4 The equipment shall then be stored at a temperature of35 ºc + 2 ºc and a relative humidity of

90 to 95 percent for a period of 22 hours .

3.3.2.5 The procedure specified in clause 3.3.2.2 to 3.3.2.4 constitute one cycle . The equipment shall be subjected to a total of three consecutive cycles as above.


and deterioration of metal parts , finishes, materials , components and contacts materials . For non hermetically sealed items, the equipment shall be disassembled and examined for effects of acid corrosion .

3.4 Recovery – If required , the equipment may be washed in running tap water for 5 minutes ,

rinsed in distilled water or demineralised water , then shaken by hand or subjected to air blast to remove droplets of water and dried for 1 hour at 55 º + 2 ºc . The equipment shall then be allowed to remain under standards recovery conditions for a period of 2 to 4 hours .

3.5 Final measurements – The equipment shall be visually examined and shall be subjected to

electrical, mechanical and other checks as specified.

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JSS 0256-01 : 1992 (Revision No. 1)


SPECIFICATIONS 4.1 Initial measurements (3.1). 4.2 The applicable procedure (see 3.3).

4.3 Disassembling in case of non-hermetically sealed items (see 3.3.1.6 and 3.3.2.6).

4.4 Final measurements ( see 3.5 ) .


46

JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 11 CORROSION (ALKALINE)

1. OBJECT 1.1 To determine the suitability of equipment for use / or storage under the influence of

atmosphere containing Potassium hydroxide. 2. A spray chamber meeting the requirements specified in 2.1 to 2.6 shall be used for the test.

Note : The chamber used for this test is similar in all respects to chamber specified for procedure 1 in Test No 12 corrosion (Salt).

2.1 The alkaline chamber shall be constructed from materials that will not be affected adversely

by the corrosive influence of the potassium hydroxide solution used in the test. 2.2 The alkaline mist shall freely circulate around the equipment under test . The liquid, which

has come in contact with the equipment under test, shall then be allowed to return to the reservoir containing the solution. Drops of liquid condense accumulating on the walls, ceiling and other parts of the chamber shall not fall on the equipment under test.


2.4 The alkaline spray shall be produced by an automiser employing compressed air which is free

from impurities.

2.5 It shall be possible to adjust the air pressure for spraying of the solution in the chamber such that the quantity of alkaline solution sprayed per hour shall be approximately one percent of the volume of the chamber.

2.6 The alkaline spray chamber or humidity chamber shall be used for storage of the equipment

under test for exposure to the conditions specified in clause 3.3.1.4 &3.3.2.4 whichever chamber is used for this purpose , it shall be capable of maintaining its working space at a temperature of 35 ºc + 2 ºc and a relative humidity of 90 to 95 percent during the periods of storage of the equipment under test . The chamber used for the purpose shall satisfy the requirements specified for Tropical Exposure .

47

JSS 0256-01 : 1992 (Revision No. 1)

3. TEST PROCEDURE 3.1 Initial Measurements – The equipments shall be visually examined and shall be subjected to

electrical, mechanical , and other checks as specified . 3.2 Preparation of Alkaline Solution - the alkaline solution shall be a 10% (weight / volume

) solution of potassium hydroxide and distilled water.

3.3 Conditioning - The equipment under test shall be subject to this test in its ‘ unpacked ‘ and switched off’ conditions . Two procedures are specified for this test . the equipment shall be subjected to one of these tests .

3.3.1 Procedure. 3.3.1.1 The equipment under test while being under the laboratory atmospheric conditions , shall be

introduced into the alkaline spray chamber the latter also being under the same conditions. 3.3.1.2 The equipment shall then be exposed to the alkaline mist with the spray operating for a

period of 2 hours under the laboratory atmospheric conditions.

3.3.1.3 The quantity of solution sprayed per hour shall be approximately one percent of the volume of the chamber.

3.3.1.4 The equipment shall then be stored at a temperature of 35 ºc + 2 ºc and a relative humidity of

90- 95 percent for a period of 7 days.

3.3.1.5 The procedure specified in clause 3.3.1.2 to 3.3.1.4 constitutes one cycle. The equipment shall be subjected to a total of four consecutive cycles as above.


and deterioration of metals parts, finishes, materials, and components and contacts materials. for non –hermetically sealed items , the equipment shall be disassemble and examined for effects of alkaline corrosion .

3.3.2 Procedure 2 3.3.2.1 The equipment under test while being under the laboratory atmospheric conditions, shall be

introduced into the alkaline spray chamber, the later also being under the same conditions. 3.3.2.2 The equipment shall then be exposed to the alkaline mist with the spray operating for a period

of 2 hours under the laboratory atmospheric conditions. 3.3.2.3 The quantity of solution sprayed per hour shall be approximately one percent of the chamber.

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JSS 0256-01 : 1992 (Revision No. 1)

3.3.2.4 The equipment shall then be stored at a temperature of 35 º c + 2 º c and relative humidity of

90 – 95 percent for a period of 22 hours . 3.3.2.5 The procedure specified in clause 33.3.1.2 to 3.3.1.4 constitute one cycles as above .


and deterioration of metal parts , finishes , materials , components and contact materials . For non – hermetically sealed items, the equipment shall be disassembled and examined for effects of alkaline corrosion .

3.4 Recovery – If required, the equipment may be washed in running water or demineralised

water , then shaken by hand or subjected to ir blast to remove droplets of water and dried for 1 hour at 55º c + 2 º c . The equipment shall then be allowed to remain under standard recovery conditions for a period of 2 to 4 hours .

3.5 Final measurements - The equipment shall be visually examined , and shall be subjected to

electrical , mechanical and other checks as specified . 4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATION . 4.1 Initial measurements (see clause 3.1 ). 4.2 Applicable procedure ( see clause 3.2 ) .

4.3 Disassemble in case of non – hermetically sealed equipment (see clause 3.3.1.6 & 3.3.2.6 ). 4.4 Recovery – (see clause 3.5) .

4.5 Final measurements (see clause 3.5 ).

4.6 Any deviation from test procedure.

49

JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 12 COROSION ( SALT )

1. OBJECT 1.1 To determine the suitability of equipment for use and / or storage in salt laden atmosphere . 2. TEST CHAMBER 2.1 A salt spray chamber meeting the requirements of clause 2.2 to 2.5 shall be used for this test

for Procedure 1 (see clause 3.3.1 ). A chamber similar to one used for Driving rain test (Test No . 7)compatible for salt spray operations shall be used for procedure 2 (see clause 3.3.2).

2.2 The salt mist shall freely circulate around the equipment under test . There shall be no direct

impingement of salt mist on the equipment under test , shall not be allowed to return to the salt solution reservoir. Drops of liquids condensate accumulating on the walls, ceiling and other parts of the chamber shall not fall on the equipment under test.


2.4 An auto miser employing compressed air, which is free from all impurities, shall produce the

salt spray.

2.5 It shall be possible to adjust the air pressure for the spraying of salt solution in the chamber such that the quantity of solution sprayed per hour shall be approximately one percent of the volume of the chamber.

2.6 The salt mist chamber or a humidity chamber shall be used for the storage of the equipment

under test for exposure to the conditions specified in 3.3.1.4 and whichever chamber is used for this purpose , it shall be capable of maintaining its working space at a temperature of 35 º c + 2 º c and relative humidity of 90 to 95 percent during the periods of storage of the equipments under test . the chamber used for this purpose shall satisfy the requirements specified for tropical exposure (test no .2.4).

3. TEST PROCEDURE 3.1 Initial measurements – The equipment shall be visually examined and shall, be electrically

and mechanically checked as specified. 3.2 Preparation of salt solution. 3.2.1 Salts given in table 4.12 – 1shall be dissolved in distilled water for preparation of the salt solution the proportion of the ingredients in the solution are to be with in 10 percent of those given in the Table 4. 12 –1 .

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JSS 0256-01 : 1992 (Revision No. 1)

TABLE 4.12 – 1 COMPOSITION OF SALT SOLUTION

INGRADIENT QUANTITY PER 1 LITRE OF SOLUTION

Sodium chloride (Na Cl)

26.5 g

Magnesium chloride (MgCl ) 2

2.4 g

Magnesium sulphate (MgSO ) 4

3.3 g

Calcium Chloride (Ca Cl)

1.1 g

Potassium chloride (K Cl ) 2

0.73 g

Sodium bi carbonate(NaHCO ) 3

0.20 g

Sodium bromide (NaBr)

0.28 g

Distilled water

To make up 1 litre of slution

3.2.2 Fresh solution shall be used for each spray . 3.3 Conditioning - The equipment under test shall be subjected to this test in its ‘un packed’

and ‘switched off’ condition . Two procedures are specified for this test . the equipment shall be subjected to one or both of these procedures as specified .

3.3.1 Procedure 1 3.3.1.1 The equipment under test , while being under the laboratory atmospheric conditions shall be

introduced in to salt spray chamber , the later also being under the same conditions . 3.3.1.2 The equipment shall then be exposed to the salt mist with the spray operating , for a period

of 2 hours under the ;laboratory atmospheric conditions . 3.3.1.3 The quantity of solution sprayed per hour shall be approximately one per cent of the

volume of the chamber . 3.3.1.4 The equipment shall then be stored at a temperature of 35 º c+ 2º c and a relative humidity of

90 to 95 percent for a period of 7 days . 3.3.1.5 The procedure specified in clause 3.3.1.2 to 3.3.1.4 constitutes one cycle . The equipment

shall be subjected to a total of four consecutive cycles as above .

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JSS 0256-01 : 1992 (Revision No. 1)

3.3.16 The equipment shall then be removed from the chamber and shall be examined for corrosion

and deterioration of metal parts , finishes, materials and components . Particular attention shall be paid to the physical examination of electrical and electronic equipment for corrosion and deposition of salt for non – hermetically sealed items , equipment shall be disassembled and examined for effects of salt corrosion .

3.3.2 Procedure 2 3.3.2.1 The equipment under test, while being under laboratory atmospheric conditions shall be

introduced into the salt spray chamber the latter also being under the same conditions . 3.3.2.2 The equipment shall then be sprayed with salt water solution as per composition given in

table 4.12-1at room temperature for a time not more than10 minutes at the rate of 152 + 25 mm/ hr.

3.3.2.3 The equipment shall then be stored at a temperature of 35 º c+ 2º c and a relative humidity of

90 to 95 percent for a period of 24 hours .

3.3.2.4 The procedure specified in clause 3.3.2.2 to 3.3.2.3 constitutes one cycle . The equipment shall be sprayed to a total of 10 cycles as above over a period not exceeding 21 days.


and deterioration of metal parts , finishes, materials and components . Particular attention shall be paid to the physical examination of electrical and electronic equipment for corrosion and deposition of salt .For non – hermetically sealed items , equipment shall be disassembled and examined for effects of salt corrosion .

3.4 Recovery – If required , the equipment may be washed in running water for 5 minutes , rinsed

in demineralised water , then shaken by hand or subjected to air blast to remove droplets of water and dried for 1 hour at 55º c + 2 º c . The equipment shall then be allowed to remain under standard recovery conditions for a period of 2 to 4 hours .

3.5 Final measurements - The equipment shall be visually examined , and shall be electrically ,

mechanically checked as specified . 4 INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATION . 4.1 Initial measurements (see clause 3.1 ). 4.2 Applicable procedure ( see clause 3.3 ) .

4.3 Disassemble for internal examination (see clause 3.3.1.6 &3.3.2.5) .

52

JSS 0256-01 : 1992 (Revision No. 1)

4.4 Recovery – (see clause 3.4) .

4.5 Final measurements (see clause 3.5). 4.6 Any deviation from the normal test procedure.

53

JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 13

MOULD GROWTH

1. OBJECT

1.1 To deter mine the resistance of equipment against Mould Growth .

2. TEST CHAMBER 2.1 A humidity chamber meeting requirements of clause 2.2 to 2.6 shall be used for this test.

2.2 The chamber shall have a well sealed door to prevent exchange of atmosphere between inside and

out side. 2.3 The chamber shall be capable of maintaining its working space at a temperature of 29 º c + 1 º c.

2.4 Any periodic change of temperature shall not exceed a rate of 1 º c per hour . 2.5 The relative humidity shall be maintained at a value greater than 90 per cent by exposing a large area

of water slurry of potassium sulphate (K 2 SO 4 ). Note –The chamber shall be fitted with a suitable fan to provide a gentle circulation of air to

all parts of the working space to aid rapid transfer of moisture to or from the salt solution . The speed of circulating air must not be too high , otherwise small drops of water or grains of

salt , on the walls of the tray holding the salt solution , may carried over in the atmosphere. It should also be ensured that the spores are not detached from the equipment under test by the air circulation .

2.6 The door of the chamber shall be opened for a few minutes, once a week to renew the oxygen supply

and to add further water to the slurry .

Note : If the chamber becomes contaminated it is desirable to clean it . The preferable method is to heat it to a temperature of 120 º c, in a moisture saturated atmosphere for 1 hour . An alternative and allowed method, when the heating can not be tolerated , is to dry it and fumigate it with propylene oxide , finally washing it with water containing a detergent and ventilating it well to remove all oxide fumes.

54

JSS 0256-01 : 1992 (Revision No. 1) 3. TEST PROCEDURE

3.1 Cultures

3.1.1 The cultures used for this test shall be obtained from an official mould research station .

Note : Owing to a large number of generations in the genetic history of the standard cultures , it is possible for them tosuffervariation in their ability to attack certain materials . the assessment of the ability requires a high degree of mycological skill and the research station supplying these cultures for the test purposes should certify that they are as suitable for this test as those previously supplied and considered acceptable.

3.1.2 The following cultures shall be used together for performing this test :

Culture Strain a) Aspergillus niger V . Tieghem b) Aspergillus terreus Thom. c) Auriobasidium pullulans (De Barry) Arnaud d) Paecilomyces Varioti Baininer e) Pencillium Funiculosum Thom. f) Pencilium Ochro- Chloran Biourge g) Scopulariopsis brevicaulis (Sacc)Bain Var Glabra

Thom h) Trichoderma Viride Pers. Ex. Fr.

3.1.3 The culture shall be supplied as spores on agar medium in glass containers with cotton plugs or as considered appropriate by the mycological institute supplying them.

3.1.4 The culture shall be stored in a refrigerator at a temperature between 5 º c and 10 º c. The cultures

shall be used for preparing the test suspension when they are between 14 and 21 days old . the stoppers shall not be removed until the mould suspension is about to be made and only one suspension shall be made from the opened container . A fresh un opened container shall be usd for each batch of the suspension .

3.2 Preparation of Mould Suspension. 3.2.1 The mould suspension shall b prepared in distilled water to which has been added 0.05 percent of a

non – fungicidal wetting agent . An agent based on N – methyl tauride (Igepon)or on dioctyl sodium sulphoccinate is suitable .

55

JSS 0256-01 : 1992 (Revision No. 1) 3.2.2 Ten milli liters of water and the required wetting agent shall be added gently to each phial or tube .

A platinum or a nichrome wire shall be sterilized by heating it to red hot state in a flame and allowed to cool . This wire shall be used to scarp gently the surface of the culture to liberate the spores . the liquid shall be gently agitated to disperse the spores without detaching mycelical fragments and the mould suspension shall then be gently decanted into a flask.

3.2.3 All the eight dispersions shall be shaken vigorously together in a flask to mix thoroughly and to

break up any clumps of spores . 3.2.4 The spore suspension thus prepared shall be used on the same day on which it is prepared and shall

not be stored for future use . 3.3 Control strips 3.3.1 The control strips called for in this test shall consist of strips of pure white filter paper socked with a

nutrient salt solution as described in clause 3.3.2. 3.3.2 The nutrient salt solution consists of a solution of the following materials in distilled water . The

quantities listed are mass of salt per liter of water.

a) Potassium Dihydrogen Orthophosphate(KH2PO4) 0.7 b) Potassium Monohydrogen Orthophosphate (K2HPO4) 0.3 c) Magnesium Sulphate (MgSO4,7H2O) 0.5 d) Sodium Nitrate (NaNO3) 2.0 e) Potassium chl0ride (KCl) 0.5 f) Ferrous sulphate (FeSO4,7H2O) 0.01 g) Sucrose 30.00

3.3.3 The control strips shall be placed in a small glass dish and covered with the nutrient salt solution .

The strip shall be removed from this solution and allowed to drain free , of drips immediately before use .

3.3.4 The control strips and the nutrient salt solution shall be freshly prepared on the same day on which

they will be used for the test. 3.4 Pre conditioning - The equipment shall not normally receive any special , cleaning treatment. Note : When required , it is permissible to clean the equipment in ethanol or in water containing a

detergent before testing ,so that mould growth caused by unsuitable materials can be distinguished from that due to a surface contamination .

56

JSS 0256-01 : 1992 (Revision No. 1) 3.5 Initial Measurements - The equipments shall be visually examined and shall be subjected to

electrical , mechanical , and other checks as specified . 3.6 Conditioning . 3.6.1 The equipment and three control strips shall be sprayed with the mixed spores suspension prepared

as in clause 3.2 .The spray shall be generated by a nozzle large enough not to be blocked by the fragments of mycelium . The spray shall be impinge on all exposed surfaces of the equipment .

3.6.2 Within 15 minutes of spraying the equipment ,the control strips shall be introduced into the chamber

whose working space is maintained at a temperature of 29 º c + 1 º c and a relative humidity of not less than 90 percent .

3.6.3 The equipment and the control strips shall not be unduly disturbed except for opening the chamber

door each week until completion of the test. 3.6.4 If the mould growth is visible on any one of the control strips when the chamber door is opened for

the first time after 7 days of starting the test , the test shall be considered void and shall be recommenced .

3.6.5 Provided that the mould growth on the control strips indicates that the conditions are suitable and

the moulds viable, the equipment shall be exposed in the chamber continuously for a total period of 28 days .

3.6.6 The equipment shall be removed from the chamber after 28 days of exposure and examined

immediately under 10 power magnification. If the equipment is not hermetically sealed , the equipment shall be disassembled and interior parts examined or evidence of mould growth or damage .

3.6.7 Unless otherwise specified there shall be no mould growth when examined as in 3.6.6. 3.7 Recovery – The equipment shall then be allowed to remainder standard recovery conditions for 2 to

4 hours. 3.8 Final measurements – The equipment shall be subjected to electrical , mechanical and other checks

as specified . 4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT SPECIFICATION . 4.1 Initial measurements (see clause 3.5 ). 4.2 Whether cleaning of the equipment is required before conditioning ( see clause 3.4 ) . 4.3 The criteria for failure if other than that specified (see clause 3.6.7). 4.4 Final measurements (see clause 3.8 ). 4.5 Any deviation from the normal test procedure .

57

JSS 0256-01 : 1992 (Revision No. 1) 5. RISK TO THE PERSONS HANDLING MOULD CULTURES 5.1 All microbial cultures are more or less harmful and need proper care and precautions for handling .

These should be handled only by persons trained in the job .

58

JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 14

ACOSTIC VIBRATION 1. OBJECT 1.1 To determine the effects of fluctuating pressure fields associated with turbulent aerodynamic flow

and acoustic noise that are characteristics of air crafts , missiles and other high performance vehicles on the equipment .

2. TEST EQUIPMEN T 2.1.1 A reverberant chamber shall be used for conducting this test . 2.1.2 The chamber shall be so such shape and construction as to produce as closely as possible , a diffuse

sound field. 2.1.3 The source opening shall be in relation to the total wall area . The volume occupied by the equipment

under test shall not exceed 10 percent of the volume of the chamber . As far as possible , it shall be possible for the equipment under test to be positioned at the center of the chamber .

2.2 Noise Source . 2.2.1 The acoustic energy supplied to the test chamber should , as far as practicable , be of a random

nature approximating to a normal distribution with amplitudes up to a peak value not less than three times the root mean square (r.m.s )value .

2.3 Measuring System . 2.3.1 The measuring and indicating instruments used with the microphones and the microphones

themselves shall be capable of handling random noise as specified in 2.2.1.The measuring system shall give the root mean square value of the sound pressure when measuring a random noise .

2.4 Microphones. 2.4.1 The microphones used shall be calibrated for random incidence. 2.5 Spectrum Measurements . 2.5.1 The sound pressure level shall be measured bands with center frequencies and band widths as

required by the relevant equipment specification.

2.6 Tolerances . 2.6.1 The accuracy of the measuring system shall correspond to the precision grade for sound level .

59

JSS 0256-01 : 1992 (Revision No. 1)

3. TEST PROCEDURE 3.1 Mounting 3.1.1 The equipment shall be mounted in the test chamber in such a manner that all appropriate

external surfaces are exposed to the acoustic field. The principal surfaces of the equipment shall not be parallel to any surfaces of the test chamber. If the equipment is long compared to its width and a single noise source is used, the equipment shall not be mounted with the long axis in line with the noise source.

3.1.2 The equipment shall be suspended in the chamber on an elastic suspension . The resonant

frequency of the suspension system and the equipment combined shall be less than 25 Hz , unless other wise stated . Care must be taken to ensure that no spurious acoustic or vibratory inputs are introduced . Where the equipment is provided with specific means of mounting , the suspensions systems should be attached to these points .where no specific means of mounting is provided ,the suspension system should be connected to the equipment in such a way that it dose not interfere with the free movement of pars of the equipment which may move independently.

3.1.3 If cables, pipes etc. are required to be connected to the equipment during the tests as required

in the relevant equipment specification, these should be arranged so as to add similar restraints and mass as in the normal installation.

3.2 Initial measurements 3.2.1 The equipment shall be visually examined and shall be subjected to electrical ,mechanical

and other checks as specified . 3.3 CONDITIONING There are two procedures . Procedure 1 is applicable for all equipment . Procedure 2 is for

equipment carried externally on air craft . The equipment shall be tested in unpacked and switched off conditions in both cases .

Procedure 1 3.3.1.1 The over all sound pressure level SPL, required by the relevant equipment specification shall

be produced in the chamber conforming to the octave band spectra given in figure 4.14 – 1 . The over all sound pressure levels (SPL ) corresponding to typical application are given in table 4.14- 1 .The relevant equipment specification shall choose one or more of these levels as required .

Note : With reference to Fig . 4.14 –1 the optional extension of the frequency spectrum from 125 Hz to 63 Hz (shown by dotted lines ) involves the assumption that the test chamber has an adequate model density at the low frequencies .If the chamber is small , the model density may be inadequate to provide a continuous spectrum for the test . the capabilities of the test chamber including the test set up should be examined before specifying the lower frequency limit below 125 Hz .

60

JSS 0256-01 : 1992 (Revision No. 1)

3.3.1.2 Measuring equipment capable of resolutions better than one octave may be used .

Appropriate reduction should be made to the octave band sound ,pressure levels in figure 4.14 – 1 to give the required over all sound pressure level . Measurements shall be made by using one microphone (or more if desired),placed in the area to be occupied by the equipment under test .

3.3.1.3 The equipment shall be mounted in the chamber as specified in 3.1 and the over all sound

pressure level shall be reestablished and monitored by not less than three microphones . A microphone should be located in proximity to each major dissimilar face of the equipment at a distance of 0.5 m from the face or half the distance to the nearest chamber wall , which ever is lesser . Where the chamber is provided with a single noise source, one microphone must be placed between the equipment and the chamber wall farthest from the noise source .

3.3.1.4 The over all sound pressure level (SPL) shall be adjusted until the average of the sound

level at each of the monitoring points is also with in + 4 and – 2 db . For larger or irregularly shaped equipments where it is not practicable to meet the latter requirement , its tolerance may be relaxed to + 6 dB . when the spread of reading s at the measuring positions dose not exceed 5dB , a simple arithmetical average of the decibel reading s may be used . For spread exceeding 5 dB , and rms summation of the individual sound pressure (not decibel values ) shall be used . The performance achieved shall be noted in the report .

3.3.1.5 The equipment shall then be exposed to the above conditions for a period stipulated in the relevant equipment specification .

Note – 1 : When testing missiles , the test should be related to nominal flight time

multiplied by a satisfy factor to be agreed between the contracting parties. In general, a maximum duration not exceeding 30 minutes should suffice.

3.3.1.6 The equipment should be operated either throughout the test or at appropriate phase of the

test in a manner representative of the most adverse duty cycle s for the equipment. A demonstration of the functional performance of the equipment should be made towards the end of the conditioning phases or if desired at the start and at intervals throughout only, the performance check should be carried out after the noise conditioning .

3.3.1.7 At the conclusion of 3.3.1.5,the noise source shall be switched off and the equipment shall be

removed from the chamber . 3.3.2 Procedure 2 3.3.2.1 Mount test item : Suspend the test item by spring or cords. IF a mounting structure is

required between the soft suspension and the test item or to hold the soft suspension care must be exercised to ensure that no spurious acoustic or vibratory inputs are introduced. The natural frequency of soft suspension shall be less than 25 Hz . The test items shall be exposed on every surface to the sound field by centrally locating it in the test chamber . . The test volume shall be no more than 10 % of test chamber volume when the test chamber is rectangular , no major surface of the test items shall be installed parallel to the chamber wall .

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JSS 0256-01 : 1992 (Revision No. 1)

3.3.2.2 Establish three reference planes perpendicular to the longitudinal axis of the equipment at

positions one sixth , one half and five sixth of the length of the equipment . In each reference plane , position here microphones , 120 degrees apart, around the equipment . each microphone shall be located within 45 cms from the surface of the equipment but not greater than one half of the distance from the nearest baffle .

3.3.2.3 The response of the three microphones on each reference plane shall be averaged to give an

average noise spectrum for each reference plane .The one third octave band sound pressure level about the entire equipment shall be shaped so that ,at the location of each of these reference planes, the frequency spectra, profile shall conform to the frequency spectral profile given in Fig 4.14.-a2 And the values as per talble4.14 -2

Note : For low acoustic facilities, which can not excite the entire frequency range at one time , it is permissible to break the test into smaller segments . The testing time for each of the segments shall be the same as required if the entire spectrum is excited simultaneously .

3.3.2.4 Captive Flight Functional Test – Expose the equipment to captive flight functional test level

computed as per table 4.14 – 2 and figure 4.14 – 2 for one hour or as specified . During the test carry out performance check as specified .

3.3.2.5 Free Flight Functional Test – Expose the equipment to captive flight endurance test levels

computed as per table4.14 – 2 and figure 4.14 – 2 for one hour or as specified.

Note : This step is not required if for a one hour endurance test , the test level LO is equal or less than the corresponding captive functional test level .

3.3.2.6 Expose the equipment to free flight functional test level computed as per table 4.14 – 2 and

figure 4.14 – 2for the maximum free flight expected at maximum q , but not less than 30 sec . during the test carry out performance checks as specified .

Note – 1 : For computation of test level and frequency spectrum , the factor (N/3T) (refer table 4.14 – 2) MER of TERR cluster carriage factor shall be used . The value of q shall be the maximum value attainable during free flight s.

Note – 2 : In the event that all free flight functional checks are made during captive

functional tests levels are lager than or equal to those desired , no free flight functional test is required .

3.4 Recovery .

3.4.1 The equipment shall then be allowed to remain under standard recovery conditions for a

period of 2 to 4 hours . 3.5 Final Measurements. 3.5.1 The equipment shall be visually examined and shall be subjected to electrical , mechanical

and other checks as specified .

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JSS 0256-01 : 1992 (Revision No. 1)


SPECIFICATION . Application procedure 1 or 2 For procedure 1 :

4.1 Details of Spectrum Measurements (see 2.5) . 4.2 Initial measurements (see 3.2) .

4.3 The overall sound pressure levels (see 3.3.1.1 and Table 4.14 – 1 ).

4.4 Lower frequency limit of the spectrum, if lower than 125 Hz (see 3.3.1.1 note ).

4.5 The duration of the test (see 3.3.1.6 ).

4.6 Details of the operations and performance checks and the terms at which they should be

made (see 3.3.1.2).

4.7 Applicability of procedure 2. If applicable

a) Captive flight functional test levels and duration (see 3.3.2.4). b) Performance checks (see 3.3.2.1 and 3.3.2.6 ). c) Captive flight endurance test levels and duration of test (see 3.3.2.5 ). 3. Free flight functional test levels and duration (see 3.3.2.6)

Both procedure 1 &2

4.8 Final Measurements (see 3.3 ). 4.9 Any deviation from the normal test procedure .

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JSS 0256-01 : 1992 (Revision No. 1)

TABLE 4.14 – 1

OVERALL SOUND PRESSURE LEVELS FOR TYPICAL APPLICATION

TYPICAL APPLICATION SPL Db

Equipment Bays of Transport Aircraft in Locations not close to Jet exhaust

130

Internal Equipment Bays of Transport Aircraft close to Jet exhaust equipment Bays remote from Jet exhaust of high performance Military Aircraft

140

Internal equipment Bays close to Jet exhaust of Military Aircraft 150

Compartments of Missiles close to large Thrust Motors Aircrafts compartments close to Gun Muzzles , reheat exhausts

160 to

165

TABLE 4.14 – 2

ACOUSTIC TEST LEVELS FOR EQUIPMENT CARRIED EXTERNALY ON AIRCRAFT

Functional Test LO xx 1,5,6,7 = 20 Log (q, q1) +11 Log(X)+7 Log (1-CosBO

+72) Fo xx 2,3 = 600 Log (X/R ) + C

Endurance test Lo xx 1,5,6,7

=

20 Log (q2, q1) + 2.5 Log(N/3TX)+functional level

fo xx 2,3 = 600 Log (X/R ) + C

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JSS 0256-01 : 1992 (Revision No. 1)

DEFINITIONS

q1 = Maximum captive flight dynamic pressure (1 bs / ft 2) 1800

Q2 = 1200 fps or maximum captive flight dynamic pressure (lbs/ ft2)(whichever is lower) . Missions (Minimum N= 3)

R = Local radious of equipment in inches (see Note 4).

X = Distance from nose of equipment along axis of equipment in inches .

T = Test time in hours(minimum T = 1 hour).

C = -200 locations within one D of either aft end of equipment or aftward of re- entrant angle .

C = 400 all other locations .

A = -6 Db/octave f. > 400 Hz

A = -2 Db/octave f. > 400 Hz

D = Maximum equipment diameter in inches (see note 4).

B = Local nose cone angle at x where Tan B = (R/ X) (Ref Fig . 4. 14 – 3 ).

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JSS 0256-01 : 1992 (Revision No. 1)

REPRESENTATIVE PARAMETRIC VALUES TO BE USED FOR CAPTIVE FLIGHT WHEN SPECIFIC

PARAARE NOT AVVAILABLE

Storage Type N Endu-rance

Local Nose Cone Angle Degrees

q max

fo Nose Sec-

fo Middle Sec-

fo Aft sec-

Air to Air Missile

100 69 1600 500 1000 500

Air- to – Ground Missile

3 12 1600 800 630 630

Dispenser

Demolition Bomb

3 24 1200 500 1000 630

Flat Nose Store

3 90 1200 400 630 315

Notes

1. Raise computed Lo level by 3 Db for an equipment carried in a TER cluster rack , by 6 Db for Amer cluster rack .

2. if calculated fo is above 2000 Hz use upper frequency limit of 2000 Hz . If calculated of is

below 200 Hz use 200 Hz .

3. Round off fo upwards to a one –third octave band center frequency.

4. For equipments which do not have circular cross sections , the radius used in the formulas shall be the radius of the circle which circumstances the cross –section of the store.

5. For locations on flat nose equipment (80º < B < 90º) where X <100 Function test

Lo = 20 Log (q1)- 6 Log (X )+ 96 rance Test Endurance Test

Lo = 20 Log (q2)- 6 Log (X )+ 96 + 2.5 Log (N/ 3T)

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JSS 0256-01 : 1992 (Revision No. 1)

6. For cylindrical section > 2D , use for locations more than one D aftward into the cylindrical

section . Lo = 20 Log (q1) + 84 Endurance Test Endurance test Lo = 20 Log (q2)+ 84+ 2.5 Log (N/ 3T) 7. For changing radius section either aft of a long cylindrical section or when x> 100 on a flat

nose equipment ,redefine x so that X = 1 at beginning of this section . Functional Test Lo = 20 Log (q1)-11 Log (X )+ 84c Endurance Test Endurance Test Lo = 20 Log (q2)-11 Log (X )+ 84+ 2.5 Log (N/3T)

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JSS 0256-01 : 1992 (Revision No. 1)

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JSS 0256-01 : 1992 (Revision No. 1)

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO . 15

VIBRATION

1. OBJECT 1.1 To determine the suitability of equipment to withstand specified severities of vibration. 2. TEST EQUIPMENT

2.1 Sinusoidal Vibration System 2.1.1 Required characteristics: The characteristics required of the vibration generator and fixture

when loaded for the conditioning process shall be as follows Basic motion 2.1.1.1 Basic Motion

The basic motion shall be sinusoidal and such that all the fixing points of the equipment are moving substantially in phase and in straight parallel lines, except as in 2.1.1.2

2.1.1.2 Transverse motion.

The maximum vibration amplitude at the fixing points of the equipment in any direction

normal to the intended (including that due to rocking, torsional vibration ,etc. ) shall not exceed 25 per cent of the specified amplitude .

Note : In some cases for example , for large equipment , it may be difficult to maintain a

limit of 25 percent . In such cases the value shall be noted and stated in the test report .

2.1.1.3 Distortion

The total rms harmonic content of the acceleration , as the fixing point of the equipment ,shall

not exceed 25 percent of the actual acceleration corresponding to the specified amplitude at the fundamental drive frequency to restore the amplitude at the fundamental frequency to the specified value. In such cases the distoration value shall be noted and stated in the test report . the distoration measurement shall cover , the frequency range up to 5000Hz or five times the driving frequency , whichever be the greater .

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JSS 0256-01 : 1992 (Revision No. 1)

2.1.2 Tolerances 2.1.2.1 Amplitude

The actual vibration amplitude in the required direction shall be equal to the specific value ,

within the following tolerances : a) At the reference point , (which may be specified by the relevant

specification)(see clause 3.2.3)

i) in the frequency range where displacement amplitude is specified : + 15 percent .

ii) in the frequency range where displacement amplitude is specified : + 10

percent .

b) At each specified control point(see clause 3.2.2)as given below :

VIBRATION AMPLITUDE TOLERANCES

Clause 2.1.2.1 (b)

TOLERANCE ON FREQUENCY

RANGE Displacement Amplitude

Acceleration Amplitude

Up to 150 Hz + 25% + 15 percent Above 150 Hz - + 25 percent

NOTE : In some Cases , for example , for large equipment and /or at high frequencies , it may be

difficult to achive the tolerances given above at some discrete frequencies within frequency range . In such cases a concession should be agreed with the responsible authority on the tolerance that are acceptable at these particular frequencies ; the result achieved shall be stated in the test report .

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JSS 0256-01 : 1992 (Revision No. 1)

2.1.2.2 Frequency

a) Measurement of frequency for resonance determination shall be made with a tolerance of + 0.5 %or + 0.5 Hz , whichever be the greater .

b) Frequency tolerances in other cases shall be + 1 Hz for frequencies up to 50 Hz and + 2

percent for frequencies above 50 Hz. 2.1.2.3 Driving Force When required control of vibration amplitude shall be supplemented by a limitation of the

driving force applied to the vibrating system . the method of force limitation (for example , based on measured driving current of force transducer) shall be as stated . Unless otherwise specified the peak driving force shall be limited to a level not less than m. a nektons , where

m = mass in kilograms of the complete moving assembly (that is vibration table , drive coil , jig or fixture and equipment under test , etc.).

a = the required acceleration level in m/s 2 2.2 RANDOM VIBRATION SYSTEM 2.2.1 Required Characteristics

The characteristics required of the vibration generator when loaded for test shall be as follows :

2.2.1.1 Basic Motion

The basic motion of the fixing points of the equipment shall be rectilinear and of a stochastic nature with a normal (gaussian) distribution of instantaneous values . they shall also have substantially identical motion.

2.2.1.2 Distribution

The instantaneous acceleration values of the vibration applied to the measuring points shall have a nominal gaussion distribution , but the peak to rms acceleration ratio shall be not less than 2.5:1. Unless otherwise specified the ASD at the lower frequencies may be reduced so that dis placement utilizes the maximum capability of the test facility but the peak to rms acceleration ratio shall no exceed 3:1 . Any enforced reduction of ASD shall be stated in the test report .

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JSS 0256-01 : 1992 (Revision No. 1) 2.2.2 TOLERANCES

2.2.2.1 Acceleration special density (ASD)

a) When a single control paint is allowed , the ASD in the intended direction shall be within + 3 dB of the specified level as determined by an analyzer having a band width not wider than 1/3 octave above 100 Hz and a band width not wider than 20 H z below 100 Hz .

b) When two or more control points are used, the ASD at each control point in the

intended direction, analysed as above should as far as practicable be within + 3 dB of the specified level or as otherwise agreed by the responsible authority . With large complex equipment it will be difficult to achieve this tolerance , in such cases the revised value shall be agreed and recorded in the test report .

c) The ASD level in the transverse direction at the control point shall be within + 5

dB of the specified value in the intended direction . 2.2.2.2 Acceleration

The total rms acceleration at each control point shall be within + 2 dB of the specified value .

2.2.2.3 Confirmation of these tolerances shall be made with an analyzer providing statistical accuracies corresponding to a BT product not less than 50 where ; B is the bandwidth of the analyzer in Hz . T is the effective sampling time in seconds .

3. TEST PROCEDURE 3.1 MOUNTING

3.1.1 The equipment, with or without isolator ,shall be fastened to the vibration table , either

directly or by means of mounting fixtures , by its normal means of attachment or as otherwise stated in the relevant Equipment specification . The use of any additional or straps shall be avoided . Any connections to the equipment (such as cables ,pipes, wires, etc.)shall be so arranged that they impose no more restraint or mass than they would when the equipment is installed in its operational position .

3.1.2 The mounting fixtures shall be such as to enable the specimen to bevibrated along the various axes specified for conditioning.

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JSS 0256-01 : 1992 (Revision No. 1) 3.1.3 If it is necessary provide brackets in order to connect the equipment (or normal means of

attachment of the equipment )to the vibration table the brackets shall be designed to be effectively rigid within the frequency range to be covered by vibration test .

3.1.4 An equipment intended for use with vibration isolators should normally be tested with its

isolators . When it is not practicable to carry out vibration test with the appropriate isolators , for example, when the equipments mounted with other equipments in a common mounting systems , or if the dynamic characteristics of the isolators at a different vibration severity , as specified . tThis severity shall be determined by multiplying the normal vibration level by the most advise transmissibility factor shall be as stated or as shown by generalized curves of Fig . 4.15 – 1 .

NOTE : The relevant equipment specification may required an additional test on

equipment with the external isolators removed in order to demonstrate the minimum structural resistance to vibration.

3.1.5 The relevant equipment specification shall state whether the effect of gravitational force is important . in this case the equipment shall be so mounted that the force acts in the same direction as it would in use . Where the effect of gravitational force is not important, the equipment may be mounted in any altitude.

3.1.6 The relevant equipment specification shall state whether the influence of stray magnetic field

is significant, and the equipment may be subjected .

3.2 CONTROL

The test is controlled by measurements made at reference point and control points related to the fixing points of the equipment.

3.2.1 Fixing point

A fixing poing is a part of the equipment in contact with the fixture or vibration table at a point where the equipment is normally fastened in service . If a part of real mounting structure is used as the fixture , The fixing point shall be taken as those of mounting structure and not of the equipment .

3.2.2 Control point

A control point is normally a fixing point . It shall be as close as possible to the fixing point and in any case shall be rigidly connected to the fixing point . if four or less fixing points exist, four representative points shall be selected and specified for use as control points.

NOTE - For large and / or complex equipment , the control points should be defined in the relevant equipment specification .

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JSS 0256-01 : 1992 (Revision No. 1) 3.2.3 Reference point

The reference points the single point from which the reference signal is obtained to confirm

the test requirements and is taken to represent the motion of the equipment . It may be a control point , or a point created by a manual or automatic processing of the signals from the control points . Unless otherwise specified the signal from the reference points shall be the average of signals from the control points . The relevant equipment specification shall state the point to be used or how it should be chosen . it is recommended that for large and / or complex equipment a fictitious point be used .

3.3 INITIAL MEASUREMENTS

The equipment shall be visually examined and electrical mechanical or any other checks shall be carried as specified.

3.4 CONDITIONS

3.4.1 Test sequence for conditioning consists of the following stages . 3.4.1.1 Initial resonance search

The equipment is vibrated (sinusoidal motion ) over the complete frequencyrangee specified .

It is checked functionally and examined for any frequency dependent effects such as mechanical resonance’s and malfunctioning. These vibration characteristics , their frequencies and the levels at which they occur are noted.

3.4.1.2 Sinusoid with frequency sweep Sinusoid with frequency sweep:-The equipment subjected to undergo Sine wave Sweeps of

specified levels , sweep rate , frequency range and duration . 3.4.1.3 Sinusoid as fixed frequency

Sinusoid as fixed frequency:- The equipment subjected to under go vibration at one or more frequencies (or at narrow band of frequency)as specified and or at the frequencies determined in initial resonance search test .The amplitude and duration shall be as specified .

3.2.1.4 Random motion

Random motion : - The equipment subjected to undergo random vibration of specified

spectrum levels , frequency range, amplitude distribution and duration . 3.4.1.5 Final resonance search The equipment is re- tested functionally and re – examined for vibration characteristics as in

initial resonance searches The frequency of each effect, determine din initial and later in the final resonancesearchis compared. the relevant equipment specification may state the action tube taken if any change of frequevy occurs .

75

JSS 0256-01 : 1992 (Revision No. 1) 3.4.2 Unless otherwise specified the equipment shall be vibrated in three mutually perpendicular

axe sin turn, which shabeso chooen that the faults are mostliky to be reveled. 3.4.3 In the relevant equipment specification requires initial and final resonance search , the

complete test sequence including resonance search shall be performed in one axis and repeated for other axes. If necessary, the sequence may be varied by the relevant equipment specification so as to allow resonance search to be carried out in more than one direction before starting the conditioning.

3.4.3 The complete sweep of the frequency range shall be carried out in order to study the behavior

of the equipment under vibration, to determine resonance frequencies and to obtain information for final resonance search. The input level shall be sufficient to excite vibration response.

Note 1 : The build up of resonance, as the excitation passes through the resonance frequency, as a function of the frequency sweep rate, the Q of the resonance and its frequency. At low frequencies the sweep rate may be decreased if necessary.

Note 2 : The frequencies at which significant resonance peaks occur (6 db

amplification of input level considered significant) shall be identified. This shall be noted for comparison with those found in the final resonance search.

3.4.5 Sinusoid with frequency sweep 3.4.5.1 The frequency sweep is transverse of the specified frequency range once in both directions,

for example 10 HZ to 1000 HZ. The sweeping shall be continuous and logarithmic, and the sweep rate shall be approximately one octave per minute. A linear sweeping approximation may be used, provided the actual sweep rate does not exceed one octave per minute at any time and the duration of passage through each octave above 60 HZ is approximately the same as with the logarithmic sweep. The duration and amplitude shall be selected from para 4.

Note : If in the course of initial resonance search, low frequency high Q resonance have

been found a check should be made that the sweep rate of one octave per minute is not too great. The maximum permissible sweep rate is given by :

Where f is the natural frequency in Hz, and Q is the amplification factor. 3.4.5.2 The frequency increase from the minimum to the maximum of the appropriate frequency

range followed by decrease of sweeps in each axis may be required to make up the specified duration. Unless otherwise specified the duration shall be equally divided on all axes.

3.4.5.3 It is permissible to cover the frequency range in stages provided the sweep time in each ` 3.4.5.4 If required, the equipment shall be operated and checked during this test for

such proportion of the total duration as may be specified.

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JSS 0256-01 : 1992 (Revision No. 1) 3.4.6 Sinusoid at fixed frequencies 3.4.6.1 Vibration shall be applied at the frequencies at which failure, malfunctioning or other

undesirable effects are likely to occur during the equipment life. These frequencies shall be selected from the following and specified in the relevant equipment specification.

a) Frequencies at which mechanical resonance’s occur. b) Frequencies at which equipment malfunctioning and/or deterioration of

performance have been noticed. c) Predetermined frequencies.

Note : In the case of an equipment mounted on isolators, the relevant equipment

specification shall state whether or not the fundamental resonance frequencies of the equipment on its isolators should be chosen for this endurance conditioning.

3.4.6.2 It is expected that the number of frequencies at 3.4.6.1 a) and b) will be small and normally

not exceeds four; the conditioning by sweep would be preferred. 3.4.6.3 While carrying out test at resonance frequencies, the driving frequency shall be so adjusted

that the resonance is always fully excited. 3.4.6.4 The duration of the test and the amplitude shall be as specified and shall be selected from

severities given in 4. Unless otherwise specified, the total duration shall be equally divided for vibration at each frequency in each of the three axes of the equipment.

3.4.7 Random vibration.

3.4.7.1 Equalisation - Prior to the application of the random vibration conditioning at the

specified level a preliminary random excitation of the actual equipment under test may be necessary at a lower level for equalization and preliminary analysis. This equalization may be done in one or more stages: for example, first at 10 bd below the specified level and then at 6 to 3 db below the specified level. It is important that the level and time of application of the vibration be kept to a minimum. The permitted set up times are as follows.

a) at 25 per cent of the specified level, no time limit. b) At 25 to 50 per cent of the specified level - 1.5 times the specified test duration.

c) At 50 to 100 per cent of the specified level - 10 per cent of the specified test duration.

Note 1 : These set up times shall not be subtracted from the specified duration of

conditioning.

Note 2 : Minor adjustments may be effected during the conditioning.

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JSS 0256-01 : 1992 (Revision No. 1)

3.4.7.2 The equipment shall be subjected to the wide band random motion severity selected from clause 4.2.2. and specified in the relevant equipment specification.

3.4.7.3 During the entire conditioning period the total rms acceleration with the specified

frequency range shall be measured and controlled. 3.4.7.4 Unless otherwise specified, equipment shall be functioning during the conditioning in

order to determine functional as well as mechanical effects. Performance check shall be made as specified. The relevant equipment specification shall also specify the stage at which these performance checks are to be made.

3.4.8 Final resonance search

The final resonance search shall be performed in the same manner as the initial resonance search. Note 1 : Prior to final resonance search term it may be necessary to provide a period

of time in which to allow the equipment to attain the same conditions as existed at the commencement of the initial resonance search for example, as regards temperature.

Note 2 : The final resonance search is not applicable, unless specified.

3.5 Final Measurements : The equipment shall be visually examined and electrical, mechanical or any other checks

shall be carried as specified. 4. SEVERITIES 4.1 SINUSOIDAL VIBRATION 4.1.1 A vibration severity is given by the combination of frequency range, vibration amplitude

and duration. The relevant equipment specification shall choose the appropriate values from those listed in 4.1.3 and 4.1.4.

4.1.2 The vibration amplitudes are specified in terms of constant displacement amplitude is

associated with corresponding value of velocity or acceleration amplitude, the relationship is as follows: -

Acceleration (m/s2) = 4 x n2 x f2 x Displacement (mm) 1000 Velocity (m/s) = 2 x n x f x Displacement (mm)

1000

Where f is frequency in Hz.

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JSS 0256-01 : 1992 (Revision No. 1)

Note : For any combination of displacement and acceleration or displacement and

velocity amplitude, a crossover frequency can be calculated from the above relationship, so that the magnitude of vibration is same at this frequency. Hence, a frequency range may be swept continuously, changing from constant displacement to constant acceleration (or constant velocity and vice versa at the crossover frequency.)

4.1.3 Frequency Range and Amplitude 4.1.3.1 The frequency range and amplitude applicable to transportation mode, deployment or

operation is given in table 4.15-1, 4.15-2, 4.15-3, 4.15-4 and 4.14-7.

Note 1 : Where equipments are deployed in both tracked and wheeled vehicles, the levels appropriate tracked vehicles shall apply.

Note 2 : For general test purposes the low frequency limit of 5 Hz is acceptable. In the

instance where the equipment and its isolators (if used) may have an unacceptable response (for example, a low frequency resonance) at a lower frequency, then the frequency range should be extended down to 2 Hz. The test level at frequencies less than 5 Hz shall be equal to the amplitude level at 5 Hz.

4.1.4 Duration

4.1.4.1 Equipment transported by vehicle, ship or aircraft : Total duration 6 hours by frequency

sweep. 4.1.4.2 Deployment in vehicles - The total duration for conditioning for deployment modes in

tracked/wheeled vehicles shall be based upon the estimated vehicle movement. This shall be subject to a maximum of 10 hours for equipment used in wheeled vehicles and Trailers. Subject to these maximum limits, the duration shall be calculated as follows :

a) Equipment used in tracked vehicles : 2 hours duration per 1600 km of estimated

movement. b) Equipment used in wheeled vehicles and trailers : 2 hours duration per 8000 km of

estimated movement. 4.1.4.3 Deployment in Ship - 1 hour conditioning at each resonance frequency or frequency

specified.

Notes - If a resonance occurs in rubber shock or vibration mounting at or below 8 Hz, the duration of test at resonance should not exceed 5 minutes.

4.1.4.4 Deployment in Helicopter - Conditioning for sinusoidal sweep is dependent on the number

of missions as given below. The sweep will be carried 5-500-5Hz in 15 minutes for each axis :

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JSS 0256-01 : 1992 (Revision No. 1)

SINUSOIDAL CYCLING TEST TIMES

No. Of Missions Cycling time per axis (minutes)

0 - 50 30

51 - 100 60

101 & above 90

4.1.4.5 Conditioning duration at frequencies 11 Hz, 22 Hz, 33 Hz and 44 Hz is as specified in figure

4.15 depending on number of missions. 4.1.4.6 For missiles carried as external stores, sinusoidal vibration for deployment do not apply.

Random vibration as specified in para 4.2.2.2. is applicable. 4.1.4.7 Operation Mode : Conditioning for operation mode is as specified in table 4.15-7. 4.1.4.8 The vibration test level may be increased and the duration decreased by application of the

equation : T1 = ( L2 )5

T2 L1 Where T1 and L2 are the duration of the test for levels L1 and L2 expressed in terms of g (acceleration due to gravity).

Note : In this test a vibration severity is given by the combination of frequency range,

ASD level and endurance duration. For each parameter the relevant equipment specification shall choose the appropriate values from those given in 4.2.2 and 4.2.3. Random vibration does apply for transportation mode and deployment modes in snips and helicopters. For deployment in vehicles either relevant sinusoidal or random vibration can be selected as specified.

4.2 RANDOM VIBRATION 4.2.1 For this test a vibration severity is given by the combination of frequency range, ASD level

and endurance duration. For each parameter the relevant equipment specification shall choose the appropriate values from those given 4.2.3 Random Vibration does not apply for transportation mode and deployment modes in ships and Helicopters. For deployment in vehicles either relevant sinusoidal or random vibration can be selected as specified.

80

JSS 0256-01 : 1992 (Revision No. 1) 4.2.2 Frequency range and ASD Level 4.2.2.1 Deployment installed in vehicles – The frequency range and ASD levels applicable to

equipment deployed in vehicles are given in Table 4.15-5.

TABLE 4.15-5 FREQUENCY RANGE AND ASD LEVELS

EQUPMENT INSTALLED IN

ASD LEVEL AND FREQUENCY RANGE

Tracked Vehicles a) Level 1 b) Level 2 Wheeled Vehicles

10 (m/s2)2 / Hz : 20 to 500 Hz 10 (m/s2)2 /Hz : 20 to 500 Hz falling to 1 m/s2)2 /Hz at 2000 Hz. (See Fig 4.15-8). 2(m/s2)2 /Hz 20 to 50 HZ falling to 0.1 (m/s2)2 /Hz at 500 Hz (See Fig 4.15-8 & 4.15-9)

Note 1 : The low frequency range may need extended below 20 Hz for those equipment

which have a low frequency response and for tests where an isolator system is included with the equipment. The ASD appropriate to 20 Hz shall be maintained subject to the amplitude limitation of 2.2.1.2. Alternatively, random vibration test may be supplemented by a low frequency sinusoidal test.

Note 2 : In tracked vehicles, vibration some time sever, is excited at frequencies

associated with track patter. Where levels in excess of the severities specified in Table 4.15-5 are anticipated, the wide random vibration test may need to be supplemented by a sinusoidal or narrow band random vibration test over the appropriate part of the frequency band.

4.2.2.2 Missile Carried by aircraft as external stores.

Equipment installed in such missiles shall be subjected to random vibration test. The test shall be carried out sequentially along each of the orthogral. The ASD level and the profile for test shall be chosen form Table 4.15-6 and Fig 4.15-10

4.2.2.3 For Air lunch missiles the test is performed to determine its compatibility to withstand and

perform in the expected dynamic environment. The test frequency spectrum shall be determined for Fig 4.15-11 and the values from Table 4.15-6. If the value thus obtained is greater than 1200 Hz, no separates acoustic test is required.

Note: The equipment must be functional during the first third and the last third duration of the test.

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JSS 0256-01 : 1992 (Revision No. 1) 4.2.2.4 The equipment shall be mounted directly to the shaker, using its normal mounting lugs and a

suitable fixture. The stiffness of the mounting fixture shall be such that it induced resonant frequencies are as high as possible but none are below one-third of any of frequencies.

4.2.2.5 Two accelerometer shall be mounted one in the vertical and the other in the lateral plane

(longitudinal direction is the axis of the equipment) to monitor the vibration response. 4.2.2.6 Vibration shall be applies at an input level sufficient to excite vibration response. The

frequencies at which significant response peaks occur shall be identified (6 db amplification of input level considered significant).

4.2.2.7 Random vibration shall be applied so that both lateral and vertical directions are tested to

their respective unless one test is able to excite both directions simultaneously . 4.2.2.8 Operational Mode – Condition for operational mode is to be selected from Table 4.15-7 and

fig. 4.15-12 and specified. 4.2.3 Duration 4.21.3.1 equipment installed in vehicles .The total duration shall be calculated

based upon the estimated vehicle movement. This shall be subjected to a maximum of 50 hours vibration conditioning for equipment used in tracked vehicles and a maximum of 10 hours vibration conditioning for equipments used in wheeled vehicle and trailers. Subjected to these maximum limits the duration shall be circulated as follows: a) Equipments used in tracked vehicles : 2 hours duration per 1600 km estimated

movement. b) Equipments used in wheeled vehicle and trailers : 2 hours duration per 8000 km

estimated movement 4.2.3.1 Missiles carried 4.2.3.2 Missiles carried by aircraft as external stores. The conditioning shall be as per Table 4.15-6 4.2.3.3 Operational mode- The duration shall be as specified in Table 4.15-7 4.2.3.4 The duration in each category and frequency range shall be converted to equivalent duration

in the most severs category for that frequency range as given below:

The sum of the duration specified in the most severe category and the equivalent durations calculated as above shall be the total duration for which the equipment shall be subjected to at the ASD level corresponding to the most severe category. However the total duration shall be limited to a maximum of 50 hours

Note : Care should be taken to ensure that the correct durations are obtained when different frequency range apply to the flight conditions in the most severe category. The overriding arm of the 50 hours endurance test is that every resonance frequency which will be encountered in service shall be subjected to a 50 hours appropriate to that frequency range

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JSS 0256-01 : 1992 (Revision No. 1) 4.2.3.5 (S1)

T2 = T1 X ------------X 2.5 S2 Where T1 and T2 are the durations of the test levels and S1 and S2 are the corresponding ASD levels. Note : In the use of accelerated testing it is important to distinguish between functioning and survival environments so that equipments are not tested for functioning in an environment in which expected to survive only.


SPECIFICATIONS 5.1 Where driving force limitation is required and if applicable, method or force limitation (See clause 2.1.2.3). 5.2 MOUNTING (See 3.1). 5.2.1 Whether equipment is to be tested with isolators. If it is impracticable to test the equipment

with isolators, the applicable severity, shall be determined as stated in clause 3.1.4. Whether additional test without isolators is required and applicable severity (See Note below clause 3.1.4).

5.2.2 Whether gravitational effects are significant (See 3.1.5). 5.2.3 Whether influence of stray magnetic ;field is important and if applicable, the acceptable limit

of magnetic interference (See clause 3.1.6). 5.3 CONTROL (See clause 3.2) 5.3.1 The control points to be used (See clause 3.2.2). 5.3.2 The reference point to be used (See clause 3.2.3) 5.4 Initial Measurements (See clause 3.2). 5.5 The axes along which the equipment is to be vibrated (See clause 3.4.2). 5.6 Whether initial resonance search to be carried out to determine only the frequencies at which

equipment malfunction and / or deterioration of performance exhibited (See clause 3.4.1.1).

5.7 The amplitude, the sweep rate if other than 1 octave per minute (see clause 3.4.2) and duration of sweep (see clause 3.4.5.2).

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JSS 0256-01 : 1992 (Revision No. 1) 5.8 Details of equipment operation and performance check if required (See clause 3.4.5.4). 5.9 The duration and amplitude for each fixed frequency (see clause 3.4.6.4). 5.10 Random motion severity (see 3.4.7.2). 5.11 Performance and stage at which to be carried (see clause 3.4.7.4). 5.12 Whether final resonance search is required (see clause 3.4.8). 5.13 Final measurement (see clause 3.5). 5.14 Severity for each conditioning specified. 5.15 Any deviation from the normal test procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

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JSS 0256-01 : 1992 (Revision No. 1)

TABLE 4.15

FREQUENCY RANGE AND AMPLITUDES FOR SINUSOIDAL

VIBRATION FOR EQUIPMENT TRANSPORTED BY VEHICLE, SHIP AND/OR AIRCRAFT.

SL. NO. CATEGORY OF

EQUIPMENT FREQUENCY

RANGE AMPLITUDE

1. 2.

Upto and including 75 kg Over 75 kg

5 to 350 Hz 5 to 15o Hz

+ 6 mm constant displacement or + 20m/s2 constant acceleration whichever the lesser. + 6 mm constant displacement or 20 m/s2 constant acceleration whichever is the lesser.

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JSS 0256-01 : 1992 (Revision No. 1)

TABLE 4.15-2

FREQUENCY RANGE AND AMPLITUDES FOR DEPLOYMENT MODE

IN VEHICLES (SINUSOIDAL VIBRATION)

CATEGORY OF EQUIPMENT

FREQUENCY RANGE

AMPLITUDE

1.

Equipment deployed in Tracked vehicles

Level 1 Lavel 2

2. Equipment deployed in Wheeled vehicles and trailers

5 to 13 Hz 13 to 500 Hz 5 to 13 Hz 13 to 142 Hz 142 to 201 Hz 201 to 2000 Hz 5 to 8 Hz 8 to 500 Hz

+ + + + + + + +

6 mm constant displacement 40 m/s2 constant acceleratrion 6 mm constant acceleration 40 m/s2 constant acceleration 0.05 mm constant displacement 80 m/s2 constant acceleration 6 mm constant displacement 15 m/s2 constant acceleration.

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JSS 0256-01 : 1992 (Revision No. 1)

TABLE 4.15-3

FREQUENCY RANGE AND AMPLITUDES FOR DEPLOYMENT MODE

IN VEHICLES (SINUSOIDAL VIBRATION)

SL. NO.

CATEGORY OF EQUIPMENT

FREQUENCY RANGE

AMPLITUDE

1. Equipment deployed in major warships (see Fig 4.15.2) Mast head region

5 to 14 Hz + 1.25 mm constant displacement



After region 5 to 23 Hz + 0.45 mm constant displacement


Main region 5 to 33 Hz + 1.25 mm constant displacement

2. Equipment deployed in minor warships

+

After region 7 to 300 Hz + 0.4 mm constant displacement or 60 mm/sec constant velocity, whichever is the lesser.

Main region 7 to 300 Hz + 0.2 mm constant displacement or 30 mm/sec constant velocity, whichever is the lesser.

3. Equipment deployed in submarines.

5 to 33Hz + 0.25 mm constant displacement

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JSS 0256-01 : 1992 (Revision No. 1)

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JSS 0256-01 : 1992 (Revision No. 1)

TABLE 4.15-4

CYCLING PERIOD, RATE AND TIME SCHEDURE CHART

FOR EQUIPMENT EXTERNALLY CARRIED STORES IN HELICOPTERS.

Excitation Sinusoidal cycling Test level curves for dwell at

Sweep time 5-500-5Hz

Curve (see Fig)

4.15-3

11 Hz 22 Hz 33 Hz 44 Hz

Vertical 15 mins A See Fig 4.15-5 VA VB VC VD

Transverse 15 mins B See Gig 4.15-6 TA TB TC TD

Longitudinal 15 mins C See Fig 4.15-7 LA LB LC LD

Durations For Duration See Fig.

4.15-4

Sinusoidal cycling test time

No. of missions Cycling time Per axis (minute)

0 - 50

50 - 100

101 - 100

30

60

90

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Fig 4.15-3 Vibration Test curves for cycling test for equipment externally carried by Helicopters.

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NUMBER OF MISSIONS

Fig : 4.15-4 Time curves for Dwell tests for equipment externally carried stores in Helicopters.

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WEIGHT OF TEST ITEM (1b)

Fig : 4.15-5 Vibration Test Curves of Dwell Tests, Vertical Axis, for Equipment Externally carried in Helicopters

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WEIGHT OF TEST ITEM (1b) Fig : 4.15-6 Vibration Test Curves of Dwell Tests, Transverse Axis, for Equipment Externally carried in

Helicopters.

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WEIGHT OF TEST ITEM (1b) Fig : 4.15-7 Vibration Test Curves of Dwell Tests, Transverse Axis, for Equipment Externally carried in

Helicopters.

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FIG : 4.15-9 RANDOM VIBRATION LEVELS FOR WHEELED VEHICLES AND TRAILERS

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TABLE 4.15-7

VIBRATION TEST LEVELS AND DURATION FOR OPERATION MODE

A. PROCEDURE SELECTION & TIME SCHEDURE CHART

Equipment Mounting

Applicable Sinusoidal

Tests Random

Test time Sinusoidal

Schedule (near axis ) Fig. 4.15-12 Sweep Random

Configuration Cycling Cycling time

Timed 5-2000-5 Hz Note

Time #

Curve

X 30 min 20 min One of P thru U

Without vibration isolators

X 30 min One of AE thru AP

X 30 min 20 min One of P thru

U X 30 min 20 min N

With vibration @ isolators

X 30 min One of AE thru AP

X 30 min 20 min N Normally with vibration

isolators but tested without isolators X 30 min AE

* For sinusoidal vibration resonance tests and cycling tests of items mounted in missiles and

weighing more than 80 pounds, the vibratory accelerations shall be reduced by + 1 g for each 20 pound increment of wt over 80 pounds. Acceleration derating shall apply only to the highest test level of the selected curve. However, the vibratory acceleration shall in no case be less than 50% of the specified curve level.

Test items of equipment normally provided with vibration isolators first shall be tested with

the isolators in place. The isolators then shall be removed and the test item rigidly mounted and subjected to the test level indicated. Isolators shall be replaced and the test item subjected to the test level indicated.

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TABLE 4.15-7 B. CURVE SELECTION CHART FOR CATEGORY

C. EQUIPMENT

Equipment location by vehicle section

Spptoximate thrust (power)

Vibration Sinusoidal

Test Curves Random

All except booster All P or Q AE AF or AG

1,00,000 kgs or less Q or R AH AJ or AK

2,00,000 kgs to 2,00,000

R or Q AK AL or AM

By individual Booster stage Over 2,00,000 T or U AM AN or AP

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TEST No. 16

ACCELERATION (STEADY STATE)

1. OBJECT 1.1 To determine the structural integrity and satisfactory performance of equipment during and

after subjection to a steady acceleration other than gravity. 2. TEST EQUIPMENT 2.1 Characteristics of the Test Machines - A centrifuge having characteristics ecified

in 2.2 to 2.2 should be used for this test, 2.2 The centrifuge shall be capable of being brought upto a speed of rotation sufficient to develop

a steady acceleration, corresponding to any of the values specified in Table 4.16-1 and 4.16-2 and shall also be capable of maintaining this ;value for the period specified in 3.3.1.4 and 3.3.2.4.

2.3 The centrifuge shall be such that the acceleration is directed towards the center of the rotating

system. In certain cases, however, the equipment may be sensitive to gyroscopic couples and it may not be possible to perform this test using the centrifuge. In such cases, the relevant equipment specification shall specify a suitable test equipment for performing this test.

2.4 The centrifuge shall have provisions to enable electrical connections to power supplies,

operation of the equipment, measurements during the test, etc., if so required. 2.5 Tangential Acceleration - While increasing the rotational speed of the centrifuge, from zero

to a value necessary to achieve the specified acceleration or when decreasing back to zero, the centrifuge shall be so controlled that the equipment is not subjected to a value of tangential acceleration greater than 10 percent of the specified steady acceleration.

2.6 Acceleration Gradient - The dimensions of the centrifuge relative to the equipment under

test, shall be such that no part of the equipment, other than flying leads, shall be subjected to a value of acceleration outside the tolerance specified in clause 2.7.

2.7 Acceleration Tolerance - If the inner dimensions of the equipment are less than 100 mm the

acceleration on all parts of the equipment (excluding flying leads) shall be within + 10 percent of the specified steady acceleration. In other cases, the acceleration on all parts of the equipment (excluding flying leads) shall be within –10 to + 30% of the specified level of acceleration.

Note : In certain cases, while testing large equipments, exceptions may have to be made to

allow for wider tolerances than those specified above, based on the availability of centrifuges in testing laboratories.

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JSS 0256-01 : 1992 (Revision No. 1) 3. TEST PROCEDURE 3.1 Method of Mounting 3.1.1 The equipment shall be fastened to the centrifuge either directly or by means of suitable

fixtures. These fixtures shall be such as to enable the equipment to be subjected to an acceleration in the direction or directions as specified. Any external connections necessary for measuring purposes shall add a minimum restraint and mass.

Note : For reasons of safety, care should be taken to prevent the equipment under test being thrown off, if the mounting attachments are broken, but any safety devices used should not introduce additional constraint during the test.

3.1.2 The equipment shall be fastened to the centrifuge through its normal means of attachments, in

its operational attitude. If isolators are used in the normal mounting of the equipment, these isolators shall also be used for mounting the equipment for testing, if so required. Any additional stays or straps shall be avoided, wherever possible.

3.1.3 If cables, pipes, etc. are required to be connected to the equipment during the test, as

specified in the relevant equipment specification, these should be so arranged as to add similar restraint and mass as in the normal installation.

3.2 Initial Measurements - The equipment shall be visually examined and shall be electrically

and mechanically checked as specified. 3.3 Conditioning - Two procedures are specified procedure 1 is applicable for use and

transportation. Procedure 2 is applicable for structural test 3.3.1 Procedure 1 3.3.1.1 The equipment shall be subjected to the test in its ‘Unpacked’ and ‘switched-off’ condition. 3.3.1.2 The equipment shall be mounted on the centrifuge as in clause 3.1 and shall be subjected to

the acceleration as specified in the Table 4.16-1. The corresponding acceleration level determined for this test shall be applied along three mutually perpendicular axes in two opposite directions.

3.3.1.3 The relevant equipment specification shall indicate in clear terms whether :

a) The equipment is required to continue to function satisfactory during and after being subjected to the appropriate acceleration.

b) The equipment is required to regain its ability to function satisfactorily after removal of

acceleration. c) The equipment is required to function satisfactorily during acceleration when partially

Loaded/energized, the value of loading of applicable, shall be specified.

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JSS 0256-01 : 1992 (Revision No. 1) 3.3.1.4 Unless otherwise specified, the acceleration shall be applied continuously for a period of 60

seconds. 3.3.2 Procedure 2 3.3.2.1 The equipment shall be subjected to this test in its ‘unpacked’ and ‘switched-off’ condition. 3.3.2.2 The equipment shall be mounted as in 3.1 and shall be subjected to the acceleration as

specified in Table 4.16-2. The corresponding acceleration as level determined for the test shall be applied along three mutually perpendicular axis and two opposite directions.

3.3.2.3 The equipment shall be examined for physical damage after the completion of the test. Its

ability to function satisfactorily, immediately after removal of the acceleration, shall be tested, if specified.

3.3.2.4 Unless or otherwise specified, the acceleration shall be applied continuously for a period of

60 seconds. 3.4 Final Measurements - The equipment shall be visually examined and shall be electrically

and mechanically checked as specified. 4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATION. 4.1 Use of isolators (see clause 3.1.2). 4.2 Initial Measurements (see clause 3.2). 4.3 The applicable test procedure or test procedures (see clause 3.3.2.3). 4.4 Details of operation of the equipment (see clause 3.3.1.3 and 3.3.2.3). 4.5 Measurements (see clause 3.4) 4.6 Any deviation from the normal test procedure.

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TABLE 4.16-1 ACCELERATION LEVELS (m/SEC2)

Max. Forward Acceleration A* Test Levels

Longitudinal Axis - Fore 1.0 A*

- Aft 0.33A

Normal Axis - Up 0.66A

- Down 0.66A

Leteral - Left 0.66A

- Right 0.66A

Note 1 : A* is the maximum forward acceleration of the missile in flight, normally

between 60-300m/sec2. It shall be obtained from the Design Authority. In case it is not known higher value shall be used.

Note 2 : The test level in any direction small not be less then 70m/sec2 for

transportation by military aircrafts. Note 3 : For air launched missiles, the test level, in any direction shall not be less than

170m/sec2.

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TABLE 4.16-2 ACCELERATION LEVELS (m/SEC2) FOR USE AND TRANSPORTAION

Max. Forward Acceleration A* Test Levels

Longitudinal Axis - Fore 1.5 A*

- Aft 0.5 A

Normal Axis - Up 1.0 A

- Down 1.0 A

Leteral - Left 1.0 A

- Right 1.0 A

Note 1 : A* is the maximum forward acceleration of the missile in flight, normally

between 60-300m/sec2. It shall be obtained from the Design Authority. In case it is not known higher value shall be used.

Note 2 : The test level in any direction small not be less then 110m/se2 for

transportation by military aircrafts. Note 3 : For air launched missiles, the test level, in any direction shall not be less than

225m/sec2.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 17

AERODYNAMIC HEATING

1. OBJECT 1.1 To determine the effects of aerodynamic heating on the missile system. 2. TEST EQUIPMENT 2.1 Method of heating 2.1.1 The method of simulating the flight condition varies from simple means of transferring the

total amount of heat, likely to be generated in actual flight by an arbitrary process to complex methods simulating the atmosphere and the heat transfer process. This implies that the heat source should have rapid response characteristics and be able to cater for different demands. The rate of application of heat should be infini9tely variable over the required range The most practicable method of simulating kinetic heating in the laboratory on full scale specimens is by controllable radiant heating.

2.1.2 A suitable heater consists of a tungsten filament enclosed by a quartz tube and connected to a

controllable electrical supply. A number of such heaters, backed by a reflecting surface can be arranged to give heating intensities ranging from 0 to 300 kw/m2 in a matter of seconds on the specimen.

2.1.3 It is important to consider absorption characteristic of the specimen, where heating flux is the

basis of control. 2.1.4 For efficient transfer of heat, it is necessary to blacken the surface of the specimen with a heat

resisting black paint whose absorption factor is 0.96 +0.02 over the temperature range – 198ºC to + 350ºC for a total radiation from a tungsten filament heated in the range of 1000ºk to 3000º K.The absorption factor must have a high degree of stability if a radiometer is to be used for control.

2.2 METHOD OF CONTROL 2.2.1 The classic equation governing the heat input to the missile system (externally) in flight is :-

q = h ( Tr - Ts ) Where q = heat of heat flow CHM -2 -1

m s

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JSS 0256-01 : 1992 (Revision No. 1)

h = heat transfer coefficient of boundary layer

CMU -2 -1 -1

m s c

Tr = Recovery temperature defined as the temperature at which ;zero

heat transfer takes place between boundary layer and missile skin.

T = T r s

( 1+ .188 m x 2ºC )

Ts = Structural Skin Temperature.

2.2.2 Simulation of Precalculated heat input. The heat input and surface temperature ar eto be

calculated as a function of time of the prescribed variation of h and T taking into account the thermal properties of the missile frame. The heaters are controlled so as to supply the system with the calculated heat input as a function of time. This may be done by a predetermined program of heater supply voltage. The preferable method is to measure the current level of heat input and use a fervor mechanism to minimize the difference between the calculated and the measured values of q by suitable variation of heater supply voltage. For the purpose of measurement of quantity of heat, radiometer may be employed, with due corrections if required. This is the case wherein surface temperature could not be measured accurately with negligible time delay.

2.2.3 Simulation of Precalculated surface temperature. The heaters are controlled by a servo

mechanism using surface temperature so as to produce calculated surface temperature as a function of time. Measurement may be made from a thermocouple on the surface where repid heating (i.e. faster than 200 C / sec is required, the control of system accuracy becomes acute as the thermal inertias of the structure and thermocouple from part of the control loop. This scheme is desirable for (i) simulation of flight temperature distribution accurately with known temperature history on each area and (ii0 hypersonic flight at high altitudes where T is vary large and h and Ts are vary small.

2.2.4 Simulation based on h and T data. From the current vacation h and T and measured value of,

T with the help of thermo couple, the exact value of heat q is computed. The current level of heat input is measured and a servo mechanism is arranged to minimize the calculated q and the measured q by suitable variation of the heater supply voltage. For this simulation, real time flight temperature distribution is necessary.

2.2.4 Simulation based on h and T data. From the current vacation h and T and measured

value of, T with the help of thermo couple, the exact value of heat q is computed. The current level of heat input is measured and a servo mechanism is arranged to minimize the calculated q and the measured q by suitable variation of the heater supply voltage. For this simulation, real time flight temperature distribution is necessary.

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JSS 0256-01 : 1992 (Revision No. 1) 3. PROCEDURE 3.1 Initial Measurement. 3.1.1 The equipment shall be visually examined and shall be subjected to electrical, mechanical and other check as specified. 3.2 CONDITIONING 3.2.1 The equipment shall be subjected to this test in its unpacked and switched off

condition. 3.2.2 The equipment while being under the laboratory atmospheric conditions shall be exposed to

the aerodynamic heating either by simulating the precalcualted heat input (sec 2.2.2) or as per the temperature distribution over the surface as a function of item (see 3.2.3) as specified in the relevant specification.

3.2.3 The total duration of the simulation shall be 1.5 times the total mission time. 3.2.4 During testing, performance check shall be carried out, as specified. 3.2.5 Recovery – The equipment shall be brought back to laboratory condition by allowing it to

cool down for sufficient period. 3.2.6 Final Measurement - The equipment shall be visually examined and shall be checked for

electrical, mechanical or any other checks as specified. 4. INFORMATION TO BE GINE IN THE RELEVANT EQUIPMENT

SPECIFICATION. 4.1 Initial measurements (see 3.1). 4.2 Precalculated heat input or Temperature distribution over the surface as a function of time

(see 3.2.2) 4.3 Duration of the test (3.2.3). 4.4 Performance check (3.2.4). 4.5 Final measurement (3.2.6). 4.6 Any deviation from the normal procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST No. 18

SHOCK

1. OBJECT 1.1 To determine the ability of the equipment to survive the effects of non-repetitive mechanical

shocks. 2. TEST EQUIPMENT 2.1 A shock machine, as described below shall be used for conducting the test. 2.1.1 Characteristics of the Shock Machine – When the equipment together with its supporting

brackets and any other load for test purposes are mounted on the shock machine, the applied shock shall, at the monitoring point, have following characteristics.

Note : In certain cases, for instance, for high reactive loads, the relevant equipment specification may allow tolerances less severe than those specified below :-

2.1.1.1 Basic Pulse Shapes – The Shock machine shall be capable of generating a pulse approximating

to one of the following nominal acceleration versus time curves :

(a) Half – sine curve which is one half cycle of a sine wave as shown by the dotted line in fig 4.18-1.

(b) Final peak saw toothe curve which is an asymmetrical triangle with a shortfall

time as shown dotted line in fig 4.18-2. The true value of the actual pulse shall be within the limit of tolerance as down by the solid lines in the relevant figure.

2.1.1.2 Velocity change tolerance - For all pulse shapes, the actual velocity change shall be within +

10 percent of the value corresponding to the nominal pulse. To determine the velocity change, the actual pulse should be integrated from 0.4D before the pulse to 0.1D after the pulse, where D is the duration of the nominal pulse (see fig 4.18-1 and 4.18-2.).

2.1.1.3 Transverse motion - The positive or negative peak acceleration at the monitoring point

perpendicular to the intended shock direction, shall not exceed at any time30 percent of the value of the peak acceleration of the nomination in the intended direction. When --- with measuring system as described in 2.1.2 .

2.1.2 Measuring System 2.1.2.1 Monitoring – The shock pulse shall be measured by an accelerometer placed at the

monitoring point. This point shall be the equipment fixing point nearest to the centre of the table surface, unless there is a equipment fixing point having a more rigid connection to the table in which case this point shall be chosen.

2.1.2.2 Accuracy - The accuracy of the measuring system shall be such that it can be determined

that the true value is within the given tolerance.

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JSS 0256-01 : 1992 (Revision No. 1) 2.1.2.3 Frequency Characteristics - The frequency response of the overall measuring system,

including the accelerometer shall within the limits shown in fig 4.18.3.

Note : When it is necessary to employ filters to reduce the effects of any high frequency resonance inherent, in the accelerometer, it reproduced wave form, to examine the amplitude and the phase characteristics of the measuring system.

3. TEST PROCEDURE 3.1 Method of Mounting 3.1.1 The equipment shall be fastened to the shock, machine by its normal means of mounting,

either directly or by means of a fixture. Any additional stays or straps shall be avoided as far as practicable.

3.1.2 The mounting fixtures, if any used, shall be such as to enable the equipment to eb submitted

to shocks along the various axis as specified in conditioning. (see 3.3) 3.1.3 External connections necessary for measuring purposes shall add a minimum of restraint and

mass. If cables, pipes etc, are required to be connected to the equipment during the test as specified, these should be arranged so as to add similar restraint and mass as in normal installation.

3.1.4 Equipment intended for use with isolators shall normally be tested with its isolators

exceptional dse – if impossible to -----------the testing the correct isolator, ----------- mounting system, than the relevant equipment specification may permit a shock test of the stated severity on the single specimen suing isolators specified for this case.

3.1.5 Gravitational effect - The relevant equipment specification shall state whether the effect of

gravitational force is important. In this case, the equipment shall be so mounted that the gravitational force acts in the same directions it would in use. Where the effect of gravitational force is not important, the equipment may be mounted in any altitude.

3.2 Initial Measurement - The equipment shall be visually examined and shall be subjected to

electrical, mechanical and other checks as a specified. 3.3 Conditioning 3.3.1 High intensity test

(a) The test method shall be used for testing equipment under the conditions of high acceleration and short time duration shock excitation.

(b) The equipment shall be subjected to two shocks in each of the three mutually

perpendicular axis; making a total of 12 shocks. The amplitude and duration of the shock pulse shall be given in fig 4.18-1 and 4.18-2 for the respective pulse shapes. The relevant equipment specification shall specify the applicable pulse shape.

112

JSS 0256-01 : 1992 (Revision No. 1) 3.4 Final Measurements - The equipment shall be visually examined and shall be subjected to

electrical, mechanical and other check as specified. 4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATION 4.1 Initial Measurements (see clause 3.2) 4.2 Pulse shapes (see clause 2.1.1.1) 4.3 Final measurements (see clause 3.4) 4.4 Any deviation from the normal test procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 19

IMPACT 1. OBJECT 1.1 To determine the ability of the equipment to survive the effect of non-repetitive impact encountered during transportation in service use. 2 TEST EQUIPMENT 2.1 An impact machine as described below shall be used for conducting the test. 2.1.1 The impact machine shall be capable of imparting shock of the required intensity to

equipment and supporting brackets, together weighing upto maximum of 275 kg. 2.1.2 Impact machine shall be fitted with a target plate to which the equipment under test is

secured. 2.1.3 The impact machine shall be fitted with a target plate to which the equipment under test is

secured. 2.1.4 The intensity of the mechanical shock delivered to the target plate by the impact machine

shall be approved means. The intensity of shock is related to the change in length of the copper as result of the blow. After a vertical blow, the length of the copper must not exceed 4.6 mm and after a lateral blow, it shall not exceed 5..3 mm. If the length of the crusher exceeds this figure after the blow the height of fall of the weight shall be increased until compliance with the above limit after the blow, the height of the fall of the weight shall not be decreased below 1.5 metres.

3. TEST PROCEDURE 3.1 Method of Mounting 3.1.1 The equipment shall be rigidly mounted through its normal points of attachment in the

normal operational attitude on the target plate. The equipment intended to be used with shock and vibration isolators shall be normally mounted on these for the test.

3.1.2 when an equipment weighs more than 275 kg, it should be --------, if practicable into sub-

assemblies of --------weight. If these are to be used only with the remainder of the main equipment, the impact machine shall have weights mounted on the target approximately 275 kg. If any of the sub-assemblies carried out without additional weights on the target plate.

3.2 Initial Measurements – The equipment shall be visually examined and subjected to electrical,

mechanical and other checks as specified.

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JSS 0256-01 : 1992 (Revision No. 1) 3.3 Conditioning 3.3.1 The equipment shall be subjected to a test method A or B as required. 3.3.1.1 Test Method A – With the equipment in ‘switched off’ condition, the target plate carrying the

equipment shall be subjected to a series of blows as specified below :- (a) Two vertical below from a weight of 184 kg falling vertically from a height of 1.5

metres. (b) Two lateral blows from a weight of 184 kg, at a radius of 1.5 metres, falling through

an angle of 60 degrees.

(c) Two end blows from a weight of 184 kg, at a radius of of 1.5 metres, falling through an angle of 60 degrees,

3.3.1.2 Test Method B – This shall be carried out in steps as follows :-

(a) Step 1, with the equipment fully operating, the target plate carrying the equipment shall be subjected to a series of blows as specified below :-

i) Two vertical blows from a weight of 184 kg falling vertically from a height of 1.5 metres.

ii) Two lateral blows from a weight of 184 kg. At a radius of 1.5 metres falling through an angle of 60 degrees.

iii) Two end blows from a weight of 1284 kg, at a radius of 1.5 metres, falling through an

angle of 60 degrees. 3.4 Final Measurements – The equipment shall be visually examined and subjected to electrical,

mechanical and other checks as specified. 4. INFORMATION TO BE GIVEN IN THE RELEVENT EQUIPMENT

SPECIFICATION. 4.1 Initial Measurements (see clause 3.2). 4.2 Application Test Method (see clause 3.3.1) 4.3 Details of operation (see clause 3.3.1.2) (a). 4.4 Final Measurements (see clause 3.4) 4.5 Any deviation from the normal test procedure.

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TEST NO. 20 DROP

1. OBJECT 1.1 To determine the ability of the equipment to withstand the shock normally induced when it is

dropped or roughly handled during its use. 2. TEST 2.1 A drop test platform meeting the requirements of clause 2.2 and 2.3 shall be used for this

test. 2.2 The drop test platform shall consist of a steel plate not less than 6.5 mm thick which has been

wet floated on and bolted down to a fully set concrete block at least 460 mm thick.

Note : It has been found from experience that plates of thickness more than 12 mm are better suited.

2.3 The surface dimensions of the steel plates prepared as in clause 2.2 shall be larger than the

largest surface of the equipment under test 2.3 The method of releasing the equipment to the drop test platform from the desired height shall

be such as to allow free fall from the position of suspension, with a minimum of disturbance at the moment of release.

3. TEST PROCEDURE 3.1 Initial Measurements - The equipment shall be visually examined and shall be subjected to

electrical, mechanical and other checks as specified. 3.2 Conditioning 3.2.1 The equipment under test shall be subjected to this test in its ‘unpacked’ and ‘switched off;

condition. 3.2.2 The equipment shall be allowed to fall freely on the drop test platform. 3.2.3 The height of the drop shall be chosen from Table 4.20-1 depending on the size and weight of

the equipment. Note : The height of drop shall be measured from the points of the equipment, nearest to

the steel plate when suspended prior to dropping.

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JSS 0256-01 : 1992 (Revision No. 1) 3.2.4 The equipment altitude from the drop (that is drop on corner, edge of face) and number of

drops on each altitude shall be appropriately selected as given in Table 4.20-1. 3.2.5 If required, the equipment shall be visually examined after each drop. 3.3 Final Measurements - The equipment shall be visual examined and shall be subjected to

electrical, mechanical and other checks as specified. 4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATION 4.1 Initial Measurements (see clause 3.1) 4.2 The required condition for the height of drop (see clause 3.2.3). 4.3 The equipment altitude (s) and number of drops in each altitude (see clause 3.2.4). 4.4 Whether visual examination is required at the end of each drop (see clause 3.2.5). 4.5 Final Measurements (see clause 3.3). 4.6 Any deviation from the normal test procedure.

TABLE 4.20-1

MASS IN kg LARGEST DIMENSIONS (cm)

HEIGHT (cm)

NO. OF DROPS AND ALTITUDE

Under 45 Under 90

Over 90 120 75

Drop on each face, edge and corner.

45 - 90 Under 90 Over 90

75 ) 60 )

Drop on each corner, Total 8 drops.

90 - 450 Under 90 -150

Over 150

60 ) 90 ) 60 )

Over 450 No limits 45 Drop on each bottom edge and bottom face, Total 5 drops.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 21 BUMP

1. OBJECT 1.1 To determine the ability of the equipment to withstand repeated bumps encountered during

use and transportation. 2. TEST PROCEDURE 2.1 Characteristics of Bump Machine - A bump machine shall be used for this test. When the

bump machine fixtures are loaded with the equipment and any other necessary load for the testing, the applied bumps shall at the monitoring points have the characteristics specified in clauses 2.2 to 2.5.

2.2 Basic Pulse Shapes - The bump shall be capable of generating a pulse approximating to one

half cycle of a sine wave as shown by dotted lines in fig. 4.21-1. The nominal pulse shall have peak acceleration of 400 m/s2 with a duration of 6 m/s2. The acceleration and time duration shall be achieved within the tolerance shown by thick lines in fig. 4.21-1.

Note : A bump repetition rate of 1 to 3 bumps per second is usually adequate to reduce

secondary bumps to a minimum.

2.3 Velocity Change - The actual velocity change shall be within + 20 percent of the value corresponding to the nominal pulse, I.e. 1.5 m/s. To determine the velocity change, the actual pulse should be integrated from 0.4D to 0.1D before and beyond the pulse where A is the duration of the nominal pulse (see fig 4.12-1).

2.4 Transverse Motion - The positive or negative peak acceleration at the monitoring point

perpendicular to the intended direction of bumps shall not exceed at any time 30 percent of the nominal value of the peak acceleration in the intended direction, when determined with a measuring system conforming to clause 2.6.

2.5 Measuring System 2.5.1 Monitoring - The acceleration measuring device shall be an accelerometer placed at the

monitoring point. This point shall be equipment fixing point nearest to the center of table surface, unless there is a --------- point having a more rigid connection to the table in which case, the latter shall be chosen.

2.5.2. Accuracy - The accuracy of measuring system shall be such that it determines the true value

with the given tolerance.

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JSS 0256-01 : 1992 (Revision No. 1) 2.5.3 Frequency Characteristics - The frequency response of the overall measuring system

including the accelerometer shall be within the limits shown in fig. 4.21-2. Note : When it is necessary to employ filters to reduce the effect of any high frequency resonance inherent in the accelerometer, it may be necessary to examine the amplitude and phase characteristics of the measuring system in order to avoid distortion of the reproduced waveform

3. TEST PROCEDURE 3.1 Initial Measurement - The equipment shall be visually examined and shall be electrically

and mechanically checked as specified. 3.2 Mounting 3.2.1 Equipment, in its ‘unpacked’ and ‘switched off’ condition, shall be fastened to the bump

machine, either directly or by means of a fixture. Mounting fixtures shall be such as to enable the equipment to be subjected to bumps along the various axis as specified for conditioning (see clause 3.3.1).

3.2.2 Equipment intended for use in an environment where bumping takes place (for example, in

moving vehicles), shall be fastened by its normal means of attachment, unless otherwise specified.

3.2.3 Equipment intended for use with isolators should normally be tested with its isolators. 3.2.4 External connections necessary for measuring purposes shall add a minimum of restraint

and mass. If cables, pipes etc., are required to be connected to the equipment during the test, as specified, these should be arranged so as to add similar restraint and mass as in normal installation.

3.2.5 When the test is employed to demonstrate a certain degree of robustness in an equipment

which is normally protected by isolators, the equipment shall, unless otherwise specified, be mounted directly to the table and the test carried out with the isolators removed or blocked. The relevant equipment specification shall clearly state the manner of mounting and the number of bumps.

3.2.6 When the bump test is employed to ascertain the capability of an equipment to withstand

transportation, other than that inherent in its service use the equipment shall be mounted as specified.

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JSS 0256-01 : 1992 (Revision No. 1) 3.2.7 When mounting the equipment on the bump machine, stays or straps additional to those

required or permitted by the relevant equipment specification shall be avoided. 3.2.8 The relevant equipment specification shall state whether the effect of gravitational force is

important. In this case, the equipment shall be so mounted that the gravitational force acts in the same direction as in the normal use.

3.3 Conditioning 3.3.1 Where the altitude of the equipment when mounted and transported kis known, and since

bumps are generally of greatest significance in one direction (usually vertical), the specified number of bumps should be applied in each of the directions specified. In this case, three mutually perpendicular directions are usually adequate.

3.3.2 The equipment shall be subjected to 4000 + 10 bumps at a peak acceleration of 400 + 40

m/s. 3.3.3 If required, the equipment shall be operated at any stage and for the period specified

performance check, if any, shall be carried out as specified. 3.4 Final Measurements - The equipment shall be visually examined for mechanical damage

and shall be subjected to electrical, mechanical and other checks as specified. 4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATION 4.1 Initial Measurements (see clause 3.1) 4.2 Details of mounting (see 3.2), whether isolators are to be used during the test (see clause

3.2.3 and number of bumps (see 3.2.5). 4.3 The altitude or directions in which the equipment to be tested (see clause 3.3.1). 4.4 Details of operation and performance check, if applicable (see clause 3.3.3) 4.5 Final Measurement (see clause 3.4) 4.6 Any deviation from the normal test procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 22

TOPPLING

1. OBJECT 1.1 To determine the ability of equipment to withstand the shocks encountered during servicing 2. TEST EQUIPMENT 2.1 A solid horizontal wooden bench top similar to that used for normal servicing operation, shall

be used for this test. The bench top shall be atleast 40 mm thick. Note : Any hard wood available locally may be used for manufacturing the bench top. 3. TEST PROCEDURE 3.1 The equipment shall be visually examined and shall be subjected to electrical, mechanical

and other checks as specified. 3.2 Conditioning 3.2.1 The equipment under test shall be subjected to this test in its ‘unpacked’ and ‘switched off’

condition. 3.2.2 The equipment, as in clause 3.2.1 shall be placed in a suitable position on the wooden bench

top described in clause 2.1. 3.2.3 Using one edge as pivot, lift the opposite edge of the equipment until one of the following

conditions occurs (whichever occurs first). (a) The equipment bottom surface makes an angle of 45º with horizontal bench top. (b) The lifted edge of the equipment has been raised 100 mm above the horizontal

bench top.

(c) The light edge of the equipment is just below the point of perfect balance. 3.2.4 The equipment shall then ;be allowed to drop back freely to the horizontal wooden bench top. 3.2.5 The Procedure given in clause 3.2.3 to 3.2.4 shall be repeated practical edges of the same

horizontal face of the equipment as pivot points for the total four drops. 3.2.6 The procedure given in clause 3.2.3 to 3.2.5 shall be repeated with the equipment resting on

other faces until it has been dropped for a total of four times on each face on which the equipment could be practically placed during servicing.

3.3 Final Measurements - The equipment then shall be visually examined and shall be subjected

to electrical, mechanical and other checks as specified

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JSS 0256-01 : 1992 (Revision No. 1) 4. INFORMATION TO BE GIVEN IN THE RELEVANT EQUIPMENT

SPECIFICATION 4.1 Initial Measurements (see clause 3.1) 4.2 Final measurements (see clause 3.3). 4.3 Any deviation from the normal test procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 23

ROADABILITY TEST 1. OBJECT 1.1 Object of this test is to ensure that the missile system mounted on its vehicle is fully prepared,

ready to fire and under switched off condition shall be capable of withstanding the hazards normally induced ;during such transportation. The system under test consists of one or more missiles assembled on its launcher mounted on its wheeled/tracked vehicle.

1.2 The vehicle used shall have capability to be mobile on high ways and unimproved cross

country terrain found around missile preparation sites and operational locations. 2. DEFINITIONS 2.1 Cross-country Terrain - Cross country terrain consists of unimproved open fields, broken

ground, loose sand of gravel road encountered by tactical vehicles supporting an army in the field.

2.2 Gravel Road - A gravel road is a level or rolling gravel trail. 2.3 Belgian Block Course - A Belgian block course consists of very tough, very hard surface,

unaffected by changes in climatic conditions. 2.4 Corrugated Track - A corrugated track is a track with alternate ridges and furrows i.e. narrow trench like depressions in any surface. This produces the resonant conditions which arise while traveling the wash board surfaces. 2.5 Wash Board Track - This is a track with corrugated metallic surface. 2.5.1 Wash Board - This has corrugations at right angles to the track and close to each other

compared to the diameter of wheel of the vehicle under test. 2.5.2 Radial Wash Board - This has corrugations at varying angles to the track and produce

twisting effect. 2.5.3 Coarse Wash Board - This has corrugation at right angle to the track but with spacing

comparable to the circumference of the wheel of the vehicle under test. 3. MOBILITY REQUIREMENTS OF VEHICLE 3.1 The vehicle track or trailer wheeled or tracked on which the missile system as the4 equipment

shall be mounted, shall meet the following requirements.

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JSS 0256-01 : 1992 (Revision No. 1) 3.1.1 Parking Brake Performance - The parking brakes shall lock the vehicle so that the wheels

will skid and do not roll on dry level brushed concrete free of loose material, when the vehicle, with maximum gross load is subjected to a towing force sufficient to move it. The vibrations and shock encountered on the applicable operating surfaces shall not cause the brakes to engage. Moving force shall be applied in both the forward and reverse direction. The parking brake shall hold the vehicle with maximum gross load whether headed up or down a 15 degree incline for wheeled and 30 degree for tracked vehicles.

3.1.2 Service Brake Performance - Under all conditions of loading, the service brake shall hold

the vehicle motionless and control it whether head up or down a 15 degree incline for wheeled and 30 degree incline for tracked vehicles and shall stop the vehicle, from a speed of 32 kmph at a distance as mentioned below from the point at which initiation of the brake actuating force begins. De-acceleration and stopping distance road surface free from lose materials. Brake shall be designed to permit braking as given below :-

3.1.2.1 Wheeled vehicles :

Delay for braking : Not more than one second. Stopping distance from a speed of 32 kms per hour (a) Vehicle with GVW 2700 t0 4500 kgs-7.6 m (b) Over 4500 kg GVW-10.7 m (c) Combination of vehicles – 13.7 m

3.1.2.2 Tracked Vehicle : Braking time-4.5 t0 6 seconds. Braking distance 15-50 miles at a speed of 25 kms/hour. Inertia actuated service brakes shall be designed to permit braking with not more than one

second delay after application of braking force. 4. TEST PROCEDURE 4.1 Initial Measurements - The equipment shall be visually examined and checked electrically

and mechanically, as specified. 4.2 Conditioning - The tyre pressure of the wheeled transport vehicle shall be adjusted for

tactical (off road) cross country service. The vehicle shall be checked for mobility requirements as given in para 3.

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JSS 0256-01 : 1992 (Revision No. 1) 4.3 Procedure 1. 4.3.1 A test track which contains the types of tracks given below, shall be constructed. The missile

system under test shelter assemblage shall be driven a number of times, as specified in the relevant equipment specification, over section of the track in the following order and at specified speeds :

(a) Coarse Wash Board (15 cms waves

spaced 1.8 meters apart )

8 kmph

(b) Belgian Block

32 kmph

(c) Radial Wash Board (5 to 10 cms waves)

24 kmph

(d) 5 cms Wash Board

16 kmph

(e)

8 cms Speed Bumps 32 kmph

4.4 Procedure 2. 4.1.1 In the absence of suitable test track as per 4.3 the missile system under test shall be hauled for

a total distance of 40 kms on a cross country drive as per details given below : 4.4.1.1 Natural/Virgin Terrains other than metalled roads, comprising of bullock cart or animal

tracks, slushy or sandy terrain such as river bed crossing, leveled or undulated boulder sections or hilly terrain for a distance of 20 km at a speed of 5 to 10 kmph.

4.4.1.2 Cross country fields with bunds of 20 to 25 cms high for a distance of 20 kms at a speed of 3

to 5 kmph. Note : - When this test is specified in the relevant equipment specification, the facilities

regarding the test tracks to be used as per procedure 1 or the alternative test tracks suggested in procedure 2 shall be mutually agreed to between the contracting parties.

4.5 Final Measurements - The vehicle and the associated missile system shall be visually

examined for damages. The missile system shall be electrically and mechanically checked as specified.

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JSS 0256-01 : 1992 (Revision No. 1) 5. INFORMATION TO BE GIVEN IN THE RELEVANT MISSILE SYSTEM

SPECIFICATION. 5.1 Initial Measurement (see clause 4.1) 5.2 Distance to be covered in various trailers. Number of times the vehicle shall be driven on test

track (see clause 4.3) 5.3 Final Measurements (see clause 4.5).

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 24

DROP TEST 1 OBJECT 1.1 To determine the ability of equipment to withstand the shock normally induced when it is

dropped or roughly handled during its transit in packed condition and on bench during its transit in packed condition and on bench during maintenance.

2. TRANSIT DROP 2.2.1 Application - This test is intended for equipment in its transit or combination case as

prepared for field use (carried to a combat situation by man, truck, rail etc). It is used to determine whether the test item is capable of withstanding the shocks normally induced by loading and unloading of equipment.

2.1.2 Restrictions - This test is not intended for shocks encountered in a normal logistic shipping

environment as experienced by shipping environment as experienced by shipping containers. 2.1.3 Test Conditions - Test levels for this test are shown in Table. The test item shall be tested

in the same configuration that is used in a combat situation. For items under 45 kg (100 pounds), the 26 drop requirement may be divided among upto 5 times dropping of the same item if desired, in any combination. Toppling of the item following will occur in the field and, therefore, toppling of the test item following its initial impact should not be restrained as long as the test item does not required drop surface.

2.1.4 Rationale - Levels for this test were set by considering how a field equipment item might

commonly be dropped. (For example, a light equipment item might be carried by one man chest high; thus, it could drop 122 cm). Field data have shown that a typical piece of man portable equipment will be dropped from heights upto 122 cm (48 inches)) an average of four to six times during its life cycle. The 26 drop requirement exists to ensure that each vulnerable position (faces, edges and corners) of a typical test item receives an impact.

2.2 Apparatus 2.2.1 The drop tester used to conduct (Transit Drop) tests shall be capable of producing the

required impacts to the test item (s). 2.2.2 - Drops for equipment mass upto 454 kg (1000 pounds) and having its largest

dimension less than 92 (36 inches) shall be made from a quick release book, or drop tester. The floor or barrier receiving the impact shall be of two inch plywood backed by concrete. For equipment over 454 kg, the floor or barrier shall be of concrete.

Test Facility

2.2.3 Controls - Controls shall be adequate to ensure that testing is conducted as specified in table.

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JSS 0256-01 : 1992 (Revision No. 1) 2.3 Procedure – Transit drop

Procedure Transit drop

Step 1 Install the test item in its transit or combination case as prepared for field use.

Step 2 From para 2 determine the height of the drops to be performed, the number of drops per test item, and the drop surface.

Step 3 Perform the required drops using the apparatus of para 3. The drops should suggested that the test item be visually and/or operationally checked periodically during the drop test to simplify and follow up on failure evaluation that may be required.

Step 4 Document the impact point or surface for each drop and any obvious damage.

Step 5 Following completion of the required drops, visually examine the test item (s).

Step 6 Document the results.

Step 7 Conduct an operational check out in accordance with the approved test plan.

Step 8 Document the results.

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TEST NO. 25

TABLE - TRANSIT DROP TEST

Weight of test Item and case

Largest dimensions Notes Height of drop No. of drops

Under 45.4 kg (100 1bs

Under 91 cm A 122 cm (48 in)

Manpacked or manportable

91 cm and over

A

76 cm (30 in)

Drop on each face edge & corners Total of 26 drops

A 76 cm (30 in)

Under 91 cm (36 in) 9

45.4 - 90.8 kg (!00-200 1bs) inclusive

1 cm and over A 61 cm (24 in)

A 61 cm (24 in)

Drop on each corner : total of 8 drops

98.8 – 454 kg (200-1000 1bs) inclusive

Under 91 cm (36 in) 91 to 152 cm (36-60 in)

B 91 cm (36 in)

Over 152 cm (60 in) B 61 cm (24 in)

Over 545 kg No limit C 46 cm (18 in) Drop on each bottom edge.Drop on bottom face or skid : Total of five drops

Notes : A. Drops shall be made from a quick release hook or drop tester. The test item shall be so

oriented that upon impact a line from the a line from the struck corner or edge to the center of gravity of the case and contents is perpendicular to the impact surface.

B. With the longest dimension parallel the floor, the transit or combination case, with the test

item within, shall be supported at the corner of one end by a block 13 cm (five inches ) in height, and at the other corner or edge of the same end by a block 30 cm (12 inches) in height. The opposite end of the case then shall be raised to the specified height at the lowest unsupported corner and allowed to fall freely.

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JSS 0256-01 : 1992 (Revision No. 1) C. While in normal transit position, the case and contents shall be subjected to the edge wise

drop test as follows (if the normal transit position is unknown, the case shall be so oriented that the two longest dimensions are parallel to the floor).

Edgewise be drop test : One edge of the base of the case shall be supported on a wall 13-15 cm (five to six inches) in height. The opposite edge shall be raised to the specified height and allowed to fall freely. The test shall be applied once to each edge of the base of the case (total of four drops).

D. The 26 drops may be divided among no more than five test times. 3.0 Bench handling 3.1.1 Applications - This should be used for equipment that may experience bench or bench type

maintenance. It is used to determine the ability of the test item to withstand the usual level of shock encountered during typical bench maintenance or repair.

3.1.2 Restrictions - This test should not be used if it can be demonstrated that the shocks from

the transit drop test are of a higher level. It is considered appropriate for medium to large test items that have a maximum dimension greater than approximately 23 cm (9.2 inches). Small items will be tested to higher levels during transit drop.

3.1.3 Test conditions - The test item shall be raised at one edge four inches above a solid

wooden bench top or until the chassis forms an angle of 45º with the bench top or until point of balance is reached, whichever is less. (The bench top must be at least 4.25 cm (1.675 inches thick.) A series of drops shall be performed in accordance with table II-3.6.

3.1.4 Rationale - The heights used during this test were set by examining the typical drops that

are commonly made by bench technicians and assembly line personnel. 3.2.0 Apparatus III - The platform used for performing these tests (bench handling) shall be a

solid wooden bench top at least 4.25 cm (1.675 inches) thick. 3.3 Procedure - Bench handling

Step 1 - Configure the item as it would be for servicing for example, with the chassis and front panel assembly --------- from its enclosures. Position the item as it would be for servicing. Step 2 - Using one edge as a pivot, lift the opposite edge of the chassis until one of the following conditions occur (whichever occurs first). a) The chassis forms an angle of 45º with the horizontal bench top. b) The lifted edge of the chassis has been raised for inches above the horizontal

top.

c) The lifted edge of the chassis is just below the point of perfect balance.

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Let the chassis drop back freely to the horizontal bench top. Repeat, using other practical edges of the same horizontal face as pivot joints, for a total of four drops.

Step 3 - Repeat step 2 with the test item resting on other faces until it has been dropped for a total of four times on each face which the test item could be placed practically during servicing. The test item shall not be operating.

Step 4 - Visually inspect the test item.

Step 5 - Document the results.

Step 6 - Operate the test item in accordance with the approved test plan.

Step 7 - Document the results.


SPECIFICATION 4.1 Initial Measurements. 4.2 The required condition for the height of drop. 4.3 The equipment attitude (s) and number of drops in each attitude. 4.4 Whether visual examination is required at the end of each drop. 4.5 Final Measurements. 4.6 Any deviation from the normal test procedure.

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JSS 0256-01 : 1992 (Revision No. 1)

TEST NO. 26

ELECTROSTATIC D DISCHARGE (ESD)

HUMAN ELECTROSTATIC DISCHARGE (HESD) Applicability : This requirement is aimed to simulate in a known and repeatable manner, the effects produced by static electricity discharging into electronics sub-systems from human beings and inanimate objects. The test is mandatory in respect of sub systems using components like CMOS, microwave mixer diodes, EEDs etc., which are vulnerable to ESD environment. In other cases, the test should be applied based on the need aspect. HESD Limits : A capacitor of 500 pf + 5% will be charged to 25,000 + volts and discharged through a 5000 Ohms + 5% resistor. The number of discharges and the discharge points have to be assessed taking into consideration of the operational environment of the missile. However, all the connector points which are projecting part of the equipment are vulnerable to ESD effects and hence should be subjected to test. Typically, ten ;discharges at a vulnerable point are considered adequate. Test Procedure : The locations where the ESD has to be simulated are identified land number of discharges are identified and number of discharges are decided. The DUT is secured firmly to the ground plane. Functional tests on the DUT are conducted as part of the ‘pre-environmental’ test and the functional parameters are recorded. While conducting the functional checks, the required number of ESD pulses are generated and deviations if any in the functional parameters have to be recorded. Care should be taken to distribute the ESD pulses uniformly all along the time during which the functional tests are carried out. If the DUT is an ‘Onboard Computer (OBC)’, the complete sequence of its functions are to be checked. If necessary a suitable test s/w package has to be developed for the purpose. After the above test, as part of ‘Post-Environmental’ test, the complete functional tests on the DUT are repeated. Pass / Eail Criteria There should not be any deviation or mal functions in the electrical performance of the DUT beyond acceptable limits. Precautions :

The test should be conducted in a shielded room. All the test instrumentation should be kept in ante-room communication and control should be through connectors on the test panel provided in between the main room and ante room.

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JSS 0256-01 : 1992 (Revision No. 1)

Power supply to DUT and test instrumentation should be from different phases and through suitable isolation transformers.

The ground plane should be grounded and better than one ohm impedance id desireable. VEHICULAR ELECTROSTATIC DISCHARGE (VESD) Applicability : This requirement is aimed to simulate in a known and repeatable manner, the effects produced by static electricity discharging into electronics sub systems from :

a) ESD due to handling. b) Static accumulation in the flight (due to missile engine charging, precipitation and friction and

induced charged due to clouds).

c) ESD occurring in the flight (due to penetration of ESD into missile through apertures caused by hatch doors, viewing windows and electrical connectors.

The test is mandatory in respect of missiles having non conductive housing in which the electronics sub-systems are located; missiles having onboard processors for guidance; missiles which are deployed by helicopters; missiles having EEDs which are initiated during flight. In other cases, the test should be applied based on the need aspect.

VESD Limits :

A capacitor of 1000 pf + 5% will be charged to 3000,000 + 500 volts and discharged through points on the system which represent a discharge to ground when coming into contact with ground objects. The number of discharges and the discharge points have to be assessed taking into consideration of the operational environment of the ;missile. Out of the equipment are vulnerable to ESD effects and hence should be subjected to test. Typically, ten ;discharges at a vulnerable point are considered adequate.

Test Procedure :

The locations where the ESD has to be simulated are identified and the number of discharges are decided. The missile (or part of it) is suspended from an insulated support stand and brought in physical contact with the high voltage toroid point. The test specimen is then charged to + 300 KV from the 100 pf source and discharged directly to gr5ound at several selected points. The most sensitive points should be selected for the purpose. An operational check on the system is made prior to start of testing. While conducting the functional checks, the required number of ESD pulses are generated and deviations if any in the functional parameters have to be recorded. Care should be taken to distribute the ESD pulses uniformally all along the time during which the functional tests are carried out. If The DUT is an ‘Onboard Computer (OBC)’, the complete sequence of its functions are to be checked. If necessary a suitable test s/w package has to be developed for the purpose. After the above test, as part of ‘Post-Environmental’ test, the complete functional tests on the DUT are repeated.

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JSS 0256-01 : 1992 (Revision No. 1) Pass & Fail Criteria : There should not be any deviation or mal-function in the electrical performance of the DUT beyond acceptable limits. The resistance of EEDs has to be checked fro change in resistance or pre-mature ignition. Precautions : Missile should not be charged with explosives. However, this requirement is not applicable in case of EEDs. The test should be conducted in a shielded room. All the test instrumentation should be kept in ante room. Communication and control should be through connectors on the test panel provided in between the main room and ante room. Power supply to DUT and test, instrumentation should be from different phases and through suitable isolation transformers.

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JSS 0256-01 : 1992 (Revision No. 1)

SECTION - 5

GUIDE LINES 1. INTORDUCTION This section provides guidelines for a series of engineering tasks that precede and follow the

conduct of environmental tests given in section 4. The objective of environmental tests are :

(a) To disclose any deficiencies or defects and plan for corrective action.

(b) To assess equipment suitability for its intended operational environment. To meet the above objectives the tests should be tailored taking into account the life cycle condition that is likely to be encountered by any specific missile system. Based on this the level for each environmental test is to be specified. Whenever the requirement cannot be ascertained objectively, the most severe level that is specified on the document shall be chosen.

2. TAILORING PROCESS Environmental requirements are to be derived taking into consideration the various natural

environmental stresses modified by equipment/carriage and stresses induced by the equipment/carriage itself. This should result in :

(a) Establishing the environmental test requirements as applicable to this system.

(b) In evolving appropriate test procedure for meeting the above requirements.

3. LIFE CYCLE PROFILE The life cycle profile covers the various phases, the equipment will encounter in its service

use such as : handling, shipping or storage prior to use; Phases between missions, such as standby or storage or transfer to and from sites; expected deployment at different geographical locations and operation/mission. The environmental stress generation mechanisms in the different phases are identified and listed in para 3.1 to 3.4

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JSS 0256-01 : 1992 (Revision No. 1) 3.1 SHIPPING / TRANSPORTATION

Handling and road transportation

Handling and rail transportation

Handling and air transportation

Handling and ship transportation

Environmental stress generation mechanism (induced)

Road shock (large bumps/pot holes), road vibration (random) handling shock dropping/over turning

Rail shock (Humping), Rail Vibration handling shock dropping over turning

In-Flight vibration on (Engine/Turbine induced, Handling over dropping/over turning

Wave vibration (sinu solid Waves--- shock (Min) blast shock handling dropping over turning

Environmental stress generation mechanism (natural)

High temperature (Dry/Humid)Low temperature Rain/Hail sand/dust

High temperature (Dry/Humid) Low temperature Rain/Hail (sand/dust)

Reduced pressure Thermal shock (long duration flights only)

High Temperature (Humid) Low temperature pain Temporary immersion salt fog

3.2 STORAGE /LOGISTIC SUPPLY


Handling & logistic Transportaion

Storage, sheltered Stop (open ) (Tent, Shed, Iglo)


Road shock (large bumps/holes), Road vibration (Random), handling shock (droping/over-turning Thermal shock.

None

None

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High Temperature (Dry/Humid) Low temperature/Freezing Rain/Hail, Sand/Dust Salt Fog, Solar Radiation, Reduced pressure

High Temperature (Dry/Humid) Low temperature/Freezing Rain/Hail, Sand/Dust Salt Fog, fungus growth chemical attack

High Temp (Dry/Humid) Low temperature/Freezing Rain/Hail, Sand/Dust Salt Fog, fungus growth chemical attack fog solar radiation

3.3 EMPLOYMENT

Deployment & use by foot soldier/(armed personnel

Deployment & use on land vehicles (wheeled/tracked)

Deployment & use abroad ships

Deployment & use on including captive (fixed/wing)


Handling shock slamming/over turning firing/blast shock, Acoustic noise explosive atmosphere, Electromagnetic interference

Road /off vibration (surface irregularities tread laying), Engine-induced vibration Acoustic noise, handling shock, (including bench, Road/off-road shock; (large bumps/holes); landmine/blast shock, weapon firing shock, vibration, Explosive atmosphere, Electromagnetic interference

Wave induced vibration (sinusoidal) Engine-induced vibration, Acoustic noise, work slam shock, Mine/blast shock weapon firing shock Explosive atmosphere, Electromagnetic interference

Runway vibration Aerody Turbul (Random tion), vre Gur vibration Acousting take of landing Manoevo acceler Airblass shock launch/landing (including bench), Aerodynamic heating Explosive atmosphe electromagnetic interference


High temperature (Dry/Humid( Low temperature/freezing, Thermal shock, Rain/Hail Sand/Dust/Mud Salt fog Solar radiation fungus growth chemical attack,

High temperature (Dry/Humid( Low temperature/freezing, Thermal shock, Rain/Hail Sand/Dust/Mud Salt fog Solar radiation fungus growth chemical attack,

High temperature (Dry/Humid( Low temperature/freezing, Thermal shock, Rain Salt fog Solar radiation fungus growth chemical attack,

High temperature (Dry/Humid( Low temperature/freezing, Thermal shock, Rain Salt fog Solar radiation fungus growth chemical attack,

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JSS 0256-01 : 1992 (Revision No. 1) 3.4 OPERATION MISSION


Launch/Manoeuvre Acceleration Handling/Launch shock Engine-induced vibration Aero-dynamic Turbulence (Random Vibration) Acoustic noise Aerodynamic atmosphere Electromagnetic interference


Rain impingement Sand/Dust impingement

Note 1 : The environmental stress events experienced by actual hardware may not always occur in the

sequence shown in this profile. The generaised profile is intended to be used as a starting point for a tailored life cycle recesses analysis and to provide confidence that all potentially significant environmental conditions have been considered.

Note 2 : The generalized profile provides only reprehensive decision making information. It does not

impose or imply a specific test order all through it can aid in suggesting potentially useful environmental test stress combinations sequence.

Note 3 : Hardware may be subjected to any or all of the shipping/transportation modes shown. The ----

-in any life cycle stress analysis, the ---pated stresses experienced by the hardware each mode should be evaluated and the significant of these incorporated in the programme.

Note 4 : The generalized profile shows only areo-environmental concern and does not attention show

operational use patterns. The ------frequency and duration of storage, shock and mission events must be considered ----mining life cycle environmental test ----- it should also be remembered that even devices must endure combinations repetitions of all these events before ultimately fired.

Note 5 : In the interest of completeness some enntal stress generating mechanisms have included for

which corresponding test included in this document. Their absen this document does not imply a lack of tance; they should be given equal concentration in the life cycle stress analysis.

4. CRITERIA FOR INVOLVING ENVIRONMENTAL REQUIREMENT AND TEST

PLANS

A detailed study of environmental storages likely to be encountered by the missile system should concurrently aid in establishing the environmental stress levels. Based on the stress levels it should be possible to choose the tests given in section 4 and fix up the test levels. While doing so the following are to be considered :

a) Probability of environmental occurrence alone or combination b) Expected effective and failure modes. c) Effect on hardware performance and mission success. d) Likelihood of problem’s disclosure by the test methods. e) Occurrence of similar environmental stress in more than one life profile phase f) Experience gained from other equipment similarly deployed.

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JSS 0256-01 : 1992 (Revision No. 1) 5. TESTING PHILOSOPHY 5.1 DEVELOPMENT TESTING (DT) Engineering development testing is required to uncover design and fabrication deficiencies as

quickly as possible and to evaluate appropriate corrective action. Many times DT is used to generate design data on the system. It should begin as early as practicable in the development phase and continues as the design matures. For these type of tests, the designers can choose appropriate stress levels in keeping with the requirements of the test. Lower level is selected to study equipment performance without excessive damage; higher level is selected to verify the equipment’s structural integrity. Levels are raised in steps to evaluate performance variation and to obtain failure data. DTT should be such as to aid in arriving at suitable design to meet the overall specification including the environmental requirements specified for the system.

5.2 QUALIFICATION TESTING : (QT) Qualification tests are carried out to verify that equipment is capable of operating to specified

performance throughout the range of environments of its service application and to provide a reasonable assurance that life requirements will be met. The results of such tests enable design clearance. This is also carried out on sampling basis on the production line for periodical surveillance.

5.3 ACCEPTANCE TESTING : (AT) In reality, materials and processes often do not work on the designers expectation.

Manufacturer’s techniques sometimes inadvertently alter the design; assembly procedures leave room for mistakes; all these would result in creeping of substandard workmanship and human error. To detect such occurrences all equipment shall undergo acceptance testing. The test levels are not as severe as in qualification testing, but sufficient enough to reveal poor workmanship and human errors contributing to production of substandard equipment.

5.4 TEST PERFORMANCE 5.4.1 The accuracy of instruments and test equipment used to control or monitor the test parameters

shall be verified prior to and following each test and then calibrated at pre-determined intervals and shall meet the requirements as specified.

5.4.2 Before testing, the equipment under test should be operated at laboratory conditions to obtain

and record data for determining compliance with the requirements and for comparison with data obtained before, during and after the environmental test. The identification and environmental test history of the specific test should be documented for failure analysis.

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JSS 0256-01 : 1992 (Revision No. 1) 5.5 COMBINED TESTS Combinations of tests may produce a more realistic representation of the effects of the

environment than a series or single tests conducted. Combined testing is encouraged wherever possible.

5.6 Post data shall include

a) Complete identification of all test equipment and accessories. b) The actual test sequence.

c) Deviation from the planned test programme.

d) The laboratory test conditions recorded periodically during the test periods.

e) Operational data.

f) Other data as specified in the individual methods or equipment specification

documents. 5.7 FAILURE CRITERIA Failure of the equipment under test to meet any one of the following conditions shall constitute

a test failure :

a) Deviation of monitored functional parameter levels beyond acceptable limits stabilized and specified in the relevant documents.

b) Non – fulfillment of specific test requirement

c) Changes to the equipment under test which could prevent the equipment from meeting

its intended service life or maintenance requirements.

d) Deviation from established environmental requirements.

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