Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. इंटरनेट मानक “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda “Invent a New India Using Knowledge” “प0रा1 को छोड न’ 5 तरफ” Jawaharlal Nehru “Step Out From the Old to the New” “जान1 का अ+धकार, जी1 का अ+धकार” Mazdoor Kisan Shakti Sangathan “The Right to Information, The Right to Live” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 2533 (1978): Geometry Boxes [PGD 22: Educational Instruments and Equipment]
Transcript
Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.
इंटरनेट मानक
“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”
“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru
“Step Out From the Old to the New”
“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan
“The Right to Information, The Right to Live”
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
“Invent a New India Using Knowledge”
है”ह”ह
IS 2533 (1978): Geometry Boxes [PGD 22: EducationalInstruments and Equipment]
I, 2 , 3: / 1
IS:2533 - 1978
Indian Standard SPECIFICATION FOR GEOMETRY BOXES
( First Revision )
First Reprint JUbiE 1989
UDC 744.34
@ Copyright 1919
BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MAHG
NEW DELHI 110002
January 1979
IS : 2533 - 1978
Indian Standard SPECIFICATION FOR GEOMETRY BOXES
( First Revision )
Educationa Instruments and Equipment Sectional Committee, EDC 77
Chairman Represenling
Dn B. SHARAN National Council of Educational Research and Training, New Delhi
Members
SHRI C. L. BATRA Towa Optics ( India ) Put-Ltd, New Delhi SIIRI RAJESR K. BATRA ( Alternate )
SHRI K. S. BIJANDARI Central Board of Secondary Education, New Delhi SJIRI P. K. B~ATTAC~ARYA National Council of Educational Research and
Training (Department of Education in Science & Mathematics ), New Delhi
DR M. M. CHAERAVARTY All Jndia Federation of University & College Tcachcrs’ Organizations, Calcutta
PROF M. BHATTACHARYYA ( AIternafe ) Plannine Commission ( Education Division ), SI~I~I S. R. CHOPRA
New’ Delhi Ministry of Industry and Civil Supplies Directorate of Technical Education, Government
of Gujarat, Ahmadabnd Ministry of Education & Social Welfare Department of Science & Technology Ambala Scicntilic Instruments Mfrs Association
(Rrgd ), Ambala Crntt
SIIRI K. M. DARQAR PROF N. R. DAVE
DR K. GOPALAN Dn 1’. K. KATTI SIIRI M. L. MADAN
SIIRI S. N. DHAWAN (Alternate) SIIRI K. MANIVANNAN
SHRI P. K.JAIN (Allemate) SHRIH.L.MEHANDRU
SHRI B.P.MITTAL
Director of Industries, Government of Haryana, Chandigarh
Dire;ctElr;;e of Industries, Delhi Administration,
Central Scientitic Instrument Organization,
\ Chandiearh
SRRI D. S. PATHANIA ( Alternate I.
( Continued on page 2 )
@ Copy& 1979
BUREAU OF INDIAN STANDARDS I
. I This publication is protected under the Indian Copyright Act ( XIV of 1957 ) and
reproduction in whole or in part by any means except with written permission of the Dublisher shall be deemed to be an infringement of copyright under the said Act. I
-
IS : 2533 - 1978
Members Representin
COXXAN~ER V. B. NAII~ Ministry of Defence ( NHQ) 1,~ CDR V. N. NARAY~NAN ( .4llerrrate )
P~OF A. V. PATANKAIZ University Grants Commission, New Delhi S3rllI LAKSIIMI SAQAR The Scientific Instruments Manufacturers’ &
Dealers’ Association ( Regd ), Ambala Cantt SHRI S. P. TUTEJ~ ( Alternate )
SIIRI B. N. Srxnh The Scientific Instrument Co Ltd, Allahabad Dn A. S. RAJPUT ( Alternate J
SHP.1 vl%n rnarr*sn ’ Modern Equipment Company, Ambala Cantt .%ITRI I-1. C. \‘l<LUJA All India Instrument Manufacturers and Dealers
PGOF V. N. WANCIIOO Association, Bombay
All India Science Teachers’ Association. New Delhi
SHRI R. I<. MOHTA ( Alternate ) SI~RI S. CIIANDRASEKHARAN, Director General, IS1 ( Ex-o@io Member)
Deputy Director ( Mech Engg)
Secretary
SIIRI S. P. ABBEY Deputy Director ( Mech Engg ), IS1
IS : 2.533 - 1978
Indian Standard
SPECIFICATION FOR GEOMETRY BOXES
( First Revision )
0. FOREWORD
0.1 This Indian Standard ( First Revision ) was adopted by the Indian Standards Institution on 26 September 1978, after the draft finalized by the Educational Instrume ts and Equipment Sectional Committee had been approved by the Met ,anical Engineering Division Council. X
0.2 This standard, first issued in 1963, has been revised to bring it in line with the actual manufacturing practices prevailing in the country. This standard covers the requirements for two grades of geometry boxes meant for school students. It is intended primarily to assist the small scale sector of the industry in regulating the quality of its production.
0.3 For the purpose of deciding whcthrr a particular requirement of tllis
standard is complied with, the final value, observed or calculated, esprcss- ing the result of a test, shall bc rounded offin ~CCWC~~C~ bvith 1S : 2-1X0*.
. The number of significant places rctair;cd ;n th e ~wlndcd off value should be the same as that of the specified value in this standard.
1. SCOPE
1.1 This standard covers the requirements of school type geometl ;- boxes of two grades, namely, Grade 1 and Grade 2.
2. INSTRUMENTS
2.1 The geometry boxes shall contain one each of the following instru- ments :
a) Compasses; b) Dividers; c) Protractor, semicircular;
dj Pair of set squares, 45”
e) Measuring scale.
*Rules for rounding off numerical
and 60”; and
values ( reCed ).
3
’ . . . IS : 2533 - 1978
3. MATERIALS
3.1 Set squares and protractor in Grade 1 geometry box shall be made of transparent plastic material, whereas in Grade 2 geometry box these shall be made of plastic material or tinplate.
3.1.1 The recommended plastic materials are polystyrene, acrylic or rigid polyvinyl chloride. The material shall be smooth, even on all sides and free from blisters, porosity and other defects.
3.1.2 The tinplate shall be bright and clean, reasonably free from spots and other defects, and shall be thoroughly and evenly coated on both sides. The tinplate shall conform to IS: 1993-1974*.
3.2 The scale shall be made of wood or transparent plastic material. The plastic material shall be as recommended in 3.1.1. Wooden scales may be supplied only in Grade 2 o c’eometry boxes and these shall be made from any of the following species of timber.
Trade Name Botanical flame
Gardenia Gardenia sp.
Parrotia Parrotiopsis jacquemontiana ( Deene ) Rehd.
Dudhi Wrightia sp.
Haldu Adina cordiflia Hook. f.
Bamboo Pseudostachyum polymorphum
3.2.1 The timber shall be thoroughly seasoned and shall be free from i;nots, cracks, sap, shakes and visible defects, such as decay, insect attack, etc, and shall be fairly straight grained.
3.3 Compasses and dividers in Grade 1 geometry box shall be made from zinc base die cast alloy ( preferabiy Alloy 2 conforming to IS : 742-196Gt ) or forged brass or rolled brass sheet conforming to grade CuZn37 of IS : 410-196’1% or chrome plated steel sheet conforming to IS : 513-1973s. In Grade 2 geometry box, compasses and dividers may be made from brass plated steel sheet conforming to IS : 513-1973s.
3.4 The needles in both the grades shall be made from suitable steel and. properly heat treated.
3.5 Boxes for the two grades shall be made fro& tin sheet or plastic material with a provision for keeping the instruments separately. The geometry boxes shall have a flat lid, well fitting, easy to open and without sharp edges. The minimum thickness of the tin sheet and plastic material used shall be 0.315 mm and 2 mm respectively for both the grades.
-*Si>&fication for cold-reduced tinplate and cold-reduced black plate (jrst revision ). tS~mitication for zinc base alloy die castings (first revision ). :SpcGfication for rolled brass plate, sheet, strip and foil ( second revision ). $Spccilication for cold rolled carbon steel sheets ( second revision ).
1.S : 2533 - 1978
4. MANUFACTURE
4.1 Compasses and dividers shall have a screwed hinge for both grades of geometry boxes.
4.2 Compasses and dividers shall be made as illustrated in Fig. 1. The compasses shall be provided with a suitable arrangement for securely holding the pencil. The diameter of the hole for holding the pencil and the thickness of the ring for tightening the pencil shall not be less than 8.2 mm and 2 mm respectively.
4.2.1 In the case of dividers, the distance between the two legs in fully closed position shall not exceed 1 mm.
4.3 The set squares, protractor in Fig. 2 to 6. In set squares centimetre graduation marks.
and the‘ scale shall be made as illustrated and the scale both the edges shall carry
FIG. 1 DIVIDER AND COMPASS ( SCREWED TYPE )
5
fS : 2533 - 1978
4.4 Set squares shall be of open centre pattern, if made from tinplate, and of centre hole or open centre pattern, if made from plastic sheet. In the open centre pattern, the minimum distance from the opening to the edge shall not be less than 15 percent of the nominal size.
4.5 Protractor shall be of open centre pattern, if made from tinplate, and of solid pattern, if made from plastic sheet.
4.6 The finish of the surface and edges of the set squares, protractor and scale shall be smooth.
5. DIMENSIONS AND TOLERANCES
5.1 Set Squares and Protractor - The dimensions and tolerances for the set squares and the protractor shall be as specified in Tables 1 and 2 respectively.
TABLE 1 DIMENSIONS AND TOLERANCES FOR SET SQUARES
( Claw 5.1 and Fig. 2 and 3 )
All dimensions in millimetres.
DESIGNATION SlZE
(1) 45 degree
100
60 degree 125
TOLERANCE ON THICKNESS THICKNESS OB ANQ~LAR LINEAR OF PLASTIC TINPLATE TOLERANCE
5.2 Scale - The dimensions for the scale shall be 160 x 25 mm. *
5.2.1 In the case of the scale made of wood, the minimum thickness at ? centre shall be not less than 3 mm ( see Fig. 6 ). r
6 c
1s : 2533 - 1978
I---- --- lOOrllm-_I
FIG.~ PROTRACTOR, SEMICIRCULAR,~PEN CENTRE PATTERN
I !-- . lOOmm_I
F1c.5 PROTRACTOR,SEMICIRCULAR,SOLID PATTERN
9
IS : 2533 - 1978
5.2.2 In the case of scale made of plastic, the thickness at the centre shall be not less than 2 mm and the scaIe shall have preferably a shaped cross section.
5.2.3 The total error for the entire length of the graduated part of the scale shall not exceed f 0.5 mm.
6. GRADUATIONS
6.1 All graduations shall be cut, stamped or engraved on set squares, protractor and scale. The graduations shall be clear, fine and filled with black colour so as to ensure good legibility without the use of magnifying glass. The thickness of the graduation lines shall not exceed 0.2 mm. The graduations shall be uniform and of lengths recommended below :
.Nominal Length
mm
a) Set squares cm graduations 10 5-mm graduations mm graduations 35
c) Scale cm graduations 8 5-mm graduations mm graduations Z.5
6.1.1 The semicircular protractor shall be double reading and shall be figured at every lo-degree graduation. The outer figures shall read clock- wise from the horizontal line starting from left and those on the inner side shall read anticlockwise starting from the opposite end. The height of the figures shall be between 2.0 and 2.5 mm for protractor. The minimum height of the figures in the case of set squares shall be 2.5 mm. The circumference of the semicircular protractor shall be graduated on the underside by radial lines for transparent protractors and on the upper side by radial lines for those made from tinplate or opaque plastic material. Set squares and the scale shall be figured at every centimetre graduation.
6.1.2 In semicircular protractor no graduations shall extend beyond the base line (which is the line joining the graduations 0” and 180” ). The base line shall be at least 3 mm away from the bottom straightedge and parallel to it.
IS:2533 - 1978
6.1.3 Two straight lines, one in continuation of graduations 0” to 180” and the other perpendicular to it through 90” graduation mark shall be drawn completely to meet at the centre in case of protractor of solid pattern as illustrated in Fig. 5. In the case of protractors of open centre pattern, a line shall be drawn joining the graduations 0” and 180”. A perpendicular line, which on extension shall coincide with the graduation mark of 90”, shall be marked to indicate the centre of the circumference.
7. MARKING
7.1 The set squares, protractor, scale, compasses and dividers shall be Iegibly and indelibly marked with maker’s name or trade-mark at a suitable place.
7.2 Each geometry box shall be marked with the maker’s name on one of its faces.
7.2.1 The geometry boxes may also be marked with the IS1 Certi- fication Mark.
NOTE - The use of the IS1 Certification Mark is governed by the provisions of the Indian Standards Institution ( Certification Marks ) Act, and the Rules and Regulations made thereunder. The IS1 Mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well-defined system of inspection, testing and quality control which is devised and supervised by IS1 and operated by the producer. IS1 marked products are also continuously checked by IS1 for conformity to that standard as a further safeguard. Details of conditions, under which a licence for the use of the IS1 Certification Mark may be granted to manufacturers or processors, may be obtained from the Indian Standards Institution.
BUREAU OF INDIAN STANDARDS
Headquarters:
Manak Bhavan, 9 Bahadur Shah Zafar Marg. NEW DELHI 110002
Telephones: 331 01 31, 331 13 75 Telegrams: Manaksanstha ( Common to all Offices)
Regional Offices: Telephone
Central Manak Bhavan, 9 Bahadur Shah Zafar Marg, 331 01 31 NEW DELHI 110002 331 1375
*Eastern : l/l4 C. I. T. Scheme VII M, V. I. P. Road, I
