Cab-MDC Cat Sec 4 Layout 1erstvak.com/docs/MDC/mdc-sredstva-izmereniya-vakuuma.pdfThermocouple gauge...

4 Vacuum measurement 208

UHV gauge controllers introduction 208-209

Nude ionization gauge tubes 210-213

Gauge head ion gauges – European style 213

Thermocouple gauge tubes 214-215

Micro pirani transmitters 216

Bourdon gauges 217

Glass envelope ionization gauge tube 218-219

207

Section 4Vacuum measurement

Caburn-MDC Europe Limited Telephone +44 (0)870 428 7646 www.caburn.co.uk

Vacuum

measurem

ent

n Bourdon gauge

n Thermocouple gauge tube

n Enclosed ionization gauge tube

n Nude ionization gauge tube

Bourdon gaugeDeflection gauges measure truepressure via deflection of a bourdontube, independent of the type of gas ina system. Bourdon tubes areconstructed in either C-tube or helicalcoil geometries and of these two,helical Bourdon tubes provide thegreatest sensitivity.

Caburn-MDC Bourdon gauges aredesigned for rough vacuummeasurements in the range of 30inches of mercury and positivepressures to 30psig. As a general rule,all vacuum components and chambersare rated for vacuum service andshould never be internally pressurized.Bourdon gauges are offered with Del-Seal™ CF metal seal flanges, Kwik-Flange™ ISO KF flanges and maleNPT pipe thread fittings.

Thermocouple gauge tubeMDC thermocouple gauge tubes offerfast and reliable vacuum measurementfrom 1 to 1x10-4 mbar.

Thermocouple gauge tubes consist oftwo basic components, a resistivefilament and a thermocouple junctionused to measure its temperature.Thermocouple gauge tubes operateon the thermal conductivity principle.Basically, they measure the thermalconductivity of a residual gas inside avacuum system, or its ability toconduct heat away from a heatedfilament. The higher the pressureinside a vacuum system the cooler thefilament or conversely, the lower thegas pressure the hotter the filamentbecomes.The thermocouple junctioninside the gauge tube is positioned onthe heated filament and is used to

monitor its temperature duringsystem evacuation. A temperaturerise or drop in the filament producesa potential rise or drop in thethermocouple junction. This potentialin millivolts is then calibrated tomicrons in a thermocouple gaugecontroller.

Because thermocouple gauge tubesand control electronics are availablefrom a multitude of manufacturers, itis important to note that individualthermocouple gauge tubes aredesigned to operate at specificfilament current ratings, which shouldbe carefully matched with a controlinstrument’s specifications. Alwaysrefer to the control electronicsmanufacturer for specifications onfilament current requirements beforepurchasing or installing athermocouple gauge tube.

Caburn-MDC UHV gauge tubesfeature all-welded construction andstainless steel casing tubes that arebakeable to 150°C. Electricalconnections are glass insulated andemploy a standard eight pin interfacewith a polarized centre post. They areoffered with Del-Seal™ CF flanges andSwagelok’s VCR® fittings. HV gaugetubes are supplied with male NPT pipethread fittings and a nickel plated steelshell assembly for maximum corrosionresistance and bakeable to 150°C.

Thermocouple gauge tubes areexpendable vacuum components andmust be replaced periodically. Mostgauges are typically calibrated forservice in air (nitrogen) andexperience extreme variations incalibration when in the presence of

Section 4 Vacuum measurement

208

Vacuum measurementIntroduction

All dimensions are nominal in millimetres unless specified Weights given are approximate


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Bourdon type gauges page 217 Thermocouple gauge tube page 214

other gases, subsequently leading toerroneous vacuum measurementreadings. An inexpensive solutionwould be to include a non-gas-dependent gauge such as a Bourdongauge to verify calibration.

Glass enclosed ionizationGauge tubeCaburn-MDC glass enclosedionization gauge tubes are designedfor high and ultrahigh vacuummeasurements between 1x10-3 to2x10-10 mbar. Glass enclosedionization tubes, commonly referredto as a Bayard-Alpert gauge tubes,consist of several componentsincluding a resistive filament, apositively charged grid and anegatively charged collector. Theresistive filament is heated toincandescence for the purpose ofemitting electrons. The grid, apositively charged wire, coiled in theshape of a spiral, attracts andaccelerates filament emitted electrons.The collector, a negatively chargedwire, is strategically placed in the pathof oncoming electrons. As electronscollide with air molecules inside thetube, the air molecules lose anelectron and become positivelycharged or ionized and thus attractedto the negatively charged collector.Upon colliding with the collector airmolecules regain their lost electronand return to their original neutralcharge. The flow of electrons fromthe collector to air molecules ismeasured and calibrated for vacuummeasurement. The number of airmolecules is directly proportional totheir ionization and in directproportion to the flow of electronssurrendered by the collector.

Nude ionization gauge tubeCaburn-MDC nude ionization gaugetubes are designed for high andultrahigh vacuum measurementsbetween 1x10-3 to 2x10-11 mbar. Liketheir glass enclosed counterparts,these are also hot cathode ionizationtypes. The main difference being theirmethod of construction.

Nude gauges allow for easyreplacement of perishable filamentsand the added durability of ceramic-to-metal electrical feedthroughinsulation which makes them bakeableto 450°C. Two nude gauge styles areoffered, these utilize resistive heatingor electron bombardment degas.


209

Vacuum measurementIntroduction



Vacuum

measurem

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Collector lead

Grid leads

Side arm tubulation

Glass envelope

Filament leads

Iridium filament

Grid

Unique VacOptix® hermetic seal design

Nude ionization gauge tube page 210Glass-enclosed ionization gauge tube page 218 Replacement filaments page 211


210

Vacuum measurementNude ionization gauge tubes



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Featuresn 10-3 to 10-11 mbar range

n DN40CF flange mounted

n Resistive heating degas

n Replaceable filament assemblies

n Mount in any position

n Bayard-Alpert type tube

UHV Series

Collector

Grid

Filament

Grid

Filament common

Internal connection

Pin-out pattern

Single filament

Pin-out pattern

Dual filament

Collector

Grid

Filament 1

Grid

Filament Common

Filament 2

n Requires minimum 34.8mm ID clearance for installation

Vacuum specificationsVacuum range 10-3 to 4x10-10 mbar

Maximum operating pressure 1x10-3 mbar

Sensitivity µ20% 10 mbar

X-ray limit 4x10-10 mbar

Construction specificationsFlange 304ss

Grid Tungsten

Filament Dual: Tungsten or iridium

Collector Tungsten

Shield coating Platinum

Base leads Soft nickel 1.5mm dia

Collector lead Soft nickel 1.0mm dia

Operating specificationsCollector -30V DC

Grid +150V DC

Filament +30V DC

Filament voltage 3 - 5V

Filament current 4 – 6A

Degas by I2R 70W

Emission 10mA

Maximum bakeout temperature 450°C


211




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Sensitivity Collector Filament Grid Applications/ UseModel Range mB Flange Bake °C Filament per Torr voltage voltage voltage Features Controller

UHTT 10-3 to 3 x 10-11 DN40CF 450 2 x W 25 0 30 180 EB Degas Customer own*

UHIR 10-3 to 3 x 10-11 DN40CF 450 2 x Th (Ir) 25 0 30 180 EB Degas Customer own*

BATT 10-3 to 5 x 10-10 DN40CF 450 2 x W 10 -30 30 150 Resistive Customer own*

BAIR 10-3 to 5 x 10-10 DN40CF 450 2 x Th (Ir) 10 -30 30 150 Resistive Customer own*

* These gauge heads are supplied as replacements for customers existing gauges only

Caburn-MDC does not supply a suitable controller for these gauges

83nominal

Knife edge

16nominal

33 nominal

Featuresn High temperature

n UHV compatible

n CF flange

n Replaceable filaments

Several of the Caburn-MDCtubes will directlyinterchange with models ofvarious manufac turers asnoted in the cross referencetable. While tubes may haveidentical electricalspecifications with tubes fromother manufacturers notlisted, pin-out dimensionsmay vary.

1 Each pack contains two filaments

I2R degas

Nominal Wtflange Description kg

DN40CF Twin tungsten filament, Bayard-Alpert gauge 0.3

DN40CF Single iridium filament, Bayard-Alpert gauge 0.3

Replacement Wtfor Description kg

BATT1 Twin tungsten filament, Bayard-Alpert gauge 0.3

BAIR1 Single iridium filament, Bayard-Alpert gauge 0.3

Reference

BATT

BAIR

Partnumber

432000

432002

22

51


n UHV compatible

n Replacement filamentassemblies for aboveionization gauge tubes

Twin tungsten filamentFilaments

Tube interchange / Cross reference table

Reference

BAIR

BARI

Partnumber

432001

432003

Replacement forDescription Granville-Phillips

Single iridium filament, BA gauge tube 274028

Replacement filament for 432002 274029

Caburn-MDCreference

BART

BAIR

Caburn-MDCpart number

432002

432003


212




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Featuresn 10-3 to 10-11 mbar rangen DN40CF flange mountedn Electron bombardment degasn Replaceable filament assembliesn Mount in any position

UHV Series

Pin-out pattern

Dual filament

Collector

Grid

Filament 1

Grid

Filament Common

Filament 2

n Requires minimum 34.8mm ID clearance for installation



Sensitivity µ20% 25 mbar

X-ray limit 2x10-11 mbar

Construction specificationsFlange 304ss

Grid Tungsten

Filament Dual: Tungsten or iridium

Collector Tungsten

Shield coating Platinum



Operating specificationsCollector 0V DC

Grid +180V DC

Filament +30V DC

Filament voltage 3 – 4.5V

Filament current 2 – 4A

Degas by EB 30 – 40W

Emission 4mA

Maximum bakeout temperature 450°C


213




Vacuum

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25.496.5Nominal

33.0 Nominal

Knife edge

Nominal17.0


n UHV compatible

n CF flange

n Stainless steelconstruction

Several of the Caburn-MDCtubes will directlyinterchange with models ofvarious manufac turers asnoted in the cross referencetable. While tubes may haveidentical electricalspecifications with tubes fromother manufacturers notlisted, pin-out dimensionsmay vary.

1 Each pack contains two filaments

EB degas


DN40CF Twin tungsten filament, UHV gauge 0.6

DN40CF Single iridium filament, UHV gauge 0.6

Replacement Per Wtfor Description pack kg

UHTT1 Twin tungsten filament, UHV gauge 2 0.3

UHIR1 Single iridium filament, UHV gauge 2 0.3

Reference

UHTT

UHIR

Partnumber

432004

432006

20

51


n UHV compatible

n Replacement filamentassemblies for aboveionization gauge tubes

Twin tungsten filamentFilaments


Reference

UHRT

UHRI

Partnumber

432005

432007

Replacement for Replacement forDescription Granville-Phillips Perkin-Elmer

Twin tungsten filament, UHV gauge tube 274022 605-7673

Replacement filament for 432004 274024 605-7671

Twin iridium filament, UHV gauge tube 274023 605-7672

Replacement filament for 432004 274025 605-7676

Caburn-MDCReference

UHTT

UHRT

UHIR

UHRI


432004

432005

432006

432007


214

Vacuum measurementThermocouple gauge tubes



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Featuresn 0.1 micron to 1000 micron Hg range

n UHV and HV tubes

n Interchangeable with other brands

n Choice of connectors

UHV and HV series

General descriptionCaburn-MDC thermocouple gauge tubes offer a fast andreliable means of measuring vacuum from 0.1 to 1000 micronHg. They can be read continuously and remotely undersevere operating conditions.

Individual thermocouple gauges operate with specific heatercurrent ratings. Gauge tubes must be matched to theinstrument’s specifications. Refer to the manufacturer’sinstructions for heater current and thermocouple output.Note Although some units are fitted with eight pins, onlyfour pins are actively used. See tube pin-out configurations onpage 215.

UHV Series tubes feature all-welded construction, stainlesssteel casings, and are bakeable to 150°C. Electricalconnections are glass insulated. They are offered with CFmini-flanges and Cajon VCR® fittings.

HV Series tubes are supplied with nickel plated steel shelland stem assemblies for corrosion resistance. They arebakeable to 150°C.

Filamentheater pins

Thermocoupleoutput pins

HeaterThermocouple

Internalvacuum

Casing

Base

Thermocouple gauge parts

Simplified TGT-2AM shown


Several of the Caburn-MDC tubes will directly interchangewith models of various manufacturers as noted in thecross reference table. Standard series tubes are equal orsuperior in performance while the high temperature/UHVseries offer even higher specifications. Other models areavailable on request.

Note Although some units are fitted with eight pins, onlyfour pins are actively used.

ModelDescription number

Televac 2A

Varian / NRC 531

Varian / NRC 531

Varian / NRC 531

Consolidated CVC GTC-004

Veeco instruments DV-1M

Hastings-Raydist DV-6M

Caburn-MDCreference

TGT-2A

TGT-5310

TGT-531M

TGT-531W

TGT-5314

TGT-1000

TGT-6000


511013

511008

511001

511003

511005

511006

511007


215

Vacuum measurementThermocouple gauge tubes



Vacuum

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Tube pin-out

33

74

Featuresn 150°C bakeout

n UHV compatible

n CF flange


DN16CF

Thermocouple gauge tube pin-out

Generally, for all thermocouple gauge tubes the pin outpatterns employ four active pins. Two of the pins supplycurrent to the heater inside the gauge head and two of thepins provide a return signal which is dependent onpressure inside the vacuum vessel. In the case of gaugetubes having eight pins, four of the pins are active and theother four are used for support only.

Heater Thermocouple pinsReference pins TC+ TC

TGT-2A 1 8 7 2

TGT-2AM 1 8 7 2

TGT-1518 1 7 5 3

TGT-1518M 1 7 5 3

TGT-1518W 1 7 5 3

TGT-5310 1 3 5 7

TGT-531M 1 3 5 7

TGT-531W 1 3 5 7

TGT-531S 1 3 5 7

TGT-1504 1 7 5 3

TGT-10001 3 5 7 –

TGT-60001 3 5 7 –

Partnumber

511013

511010

511004

511000

511002

511008

511001

511003

511009

511005

511006

511007

1 AC connection on heater pins; DC connection on TC pins

Pressure Heater Response Output @ 55Ω WtDescription range (mbar) current (mA) time (sec) and 0.01øHg (mV) kg

DN16CF 0.1 – 1000 95 < 0.2 9.1 0.1

DN16CF 0.1 – 1000 15 - 18.5 < 0.1 10 0.1

DN16CF 0.1 – 2500 163 < 0.1 13.5 – 14.5 0.1

Reference

TGT-2AM

TGT-1518M

TGT-531M

Partnumber

511010

511000

511001

69

33

Featuresn 150°C bakeout

n UHV compatible

n 34” VCR® fitting


19.1 34” VCR®

Pressure Heater Response Output @ 55Ω WtDescription range (mbar) current (mA) time (sec) and 0.01øHg (mV) kg

19 (34”) VCR® 0.1 - 1000 15 - 18.5 < 0.1 10 0.1

19 (34”) VCR® 0.1 - 2500 163 < 0.1 13.5 - 14.5 0.1

Reference

TGT-1518W

TGT-531W

Partnumber

511002

511003

TGT-2AM

TGT-1518W


216

Vacuum measurementMicro Pirani transmitters



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n Very small internal volume

n Integrated electronics

n High temperature stability

n Easy pirani calibration

n Small dimensions

n Accuracy

Micro piraniMeasuring range 1 x 10-5 to 1 x 103 mbar

Maximum pressure 3000 mbar

Output voltage 0-10V

Temperature effect on offset <0.3 mV/°C

Materials exposed to vacuum Silicon, SiO2, Si3N4, gold,

epoxy resin, stainless steel, aluminium

Accuracy ±3% typical in 10-4 to 108 mbar range

DescriptionNew pirani sensor technology incorporating careful designof the temperature compensation circuit has made itpossible to extend the measuring range of the pirani gaugedownwards by an order of magnitude to 1x10-5 mbar.

Thermal conductivity of the gas is measured in a very smallcavity integrated in a 1x1mm silicon chip. The nonlinear 0-10V DC output is easily converted to pressure by using asimple algorithm with only three calibration constants foreach gas.

Micro pirani model MPI is mounted on a DN16KF flange.(Other flange mounts are available to order). All modelsare offered with either aluminium or stainless steel bodies.

Dual trans and dual trans+ models combine the advantagesof a piezo and a micro pirani transmitter in one instrumentmounted on a DN16KF flange.

Transmitters are not supplied with a cable.

Pressure BodyDescription range material

Micro pirani 1 x 10-5 to 1 x 10-3 mbar Aluminium

Dual trans 1 x 10-5 to 1999 mbar Aluminium

Dual trans+ 1 x 10-5 to 3999 mbar Aluminium

Micro pirani 1 x 10-5 to 1 x 10-3 mbar Stainless steel

Dual trans 1 x 10-5 to 1999 mbar Stainless steel

Dual trans+ 1 x 10-5 to 3999 mbar Stainless steel

Reference

MPI-K16

DUT1-K16

DUT2-K16

SMPI-K16

SDUT2-K16

SDUT4-K16

Partnumber

2604010

2604030

2604032

2604015

2604035

2604037

Micro pirani 1 x 10-5 to 1 x 103 mbar

The micro pirani measures the thermal conductivity of theresidual gas. It is based on a 1x1mm micro mechanic chipwith resistors for measuring the thermal conductivity andthe ambient temperature. This technology together withadvanced circuit design offers excellent performance. Themicro pirani cannot be used in corrosive environments.The measured gas must be compatible with silicon, Si02,Si3N4, gold, epoxy resin, Viton®, stainless steel and nickel.Normally a standard pirani cannot be used in explosiveenvironments because the filament is kept at a constanttemperature of 150°C or higher. The sensor element ofthe micro pirani is kept at a temperature only 30°C aboveambient allowing the use in some explosive environments.

Dual trans 1 x 10-5 to 2000 mbar

The dual trans is a combination of a piezo and a micropirani into one transmitter. The advantages of the piezofrom overpressure down to 1 mbar combined with thewide measuring range of the micro pirani results in atransmitter covering more than 8 decades with highaccuracy. For media compatibility of the dual trans refer tothe micro pirani and the piezo.

Dual trans+ 1 x 10-5 to 4000 mbar

The dual trans+ is designed for vacuum applications whereoverpressure may occur. It can measure up to 4000 mbar.

Accuracy

Typical values are normally ±10 to 15% in a range down to10-3 mbar.


217

Vacuum measurementBourdon gauges



Vacuum

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Featuresn Large easy-to-read dial

n Measures vacuum to 1bar and overpressure to 1bar

n CF, KF, or NPT mounting

n Stainless steel construction

DescriptionProvides a quick visual check of roughing line pressures.

Note These gauges are intended for vacuum use with other Caburn-MDC components and as such are not ratedfor oxygen service.

30Ø74

67

125

1/4” female to 1/8” male NPTadaptor – supplied withunflanged model only.

A

Low vacuum series

Nominal Flange Ω Wtflange OD A kg

Flanged

DN16CF 34 102 0.1

DN40CF 70 107 0.3

DN16KF 30 107 0.2

DN25KF 40 107 0.2

DN40KF 55 107 0.3

DN50KF 75 107 0.3

Pipe thread

NPT thread Includes one 14” female to 1

8” male air fitting 0.1

Reference

075-VG

150-VG

K075-VG

K100-VG

K150-VG

K200-VG

VG

Partnumber

432014

432016

432010

432011

432012

432013

432020

Pressure / vacuum gauge

n 63.5 diameter gauge face

n On NPT model only, removable adaptor allows either 1/8” or 1/4” NPT thread mounting


218

Vacuum measurementGlass envelope ionization gauge tubes



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Side arm glass envelope ionization gauge tubes

Featuresn Non-burnout design allows momentary exposure

to atmosphere

n Choice of Pyrex®, Kovar® and CF flange

n ISO KF flange optional

Collector lead

133nominal

57

Grid leads

Filament leads

83or86

nominal

nominal

Pin-out pattern



Pumping speed Ionic 0.06 litres/sec – N2 (1mA)

X-ray limit 2x10-10 mbar – N2 (approx.)

Construction specificationsEnvelope Nonex

Grid “Non-sag” tungsten 0.7mm dia

Filament Hairpin thoria coated iridium

Collector Tungsten, 0.254mm dia

Shield coating Platinum, internally connected to filament



Internal volume 220cm3 (not including tubulation)

Operating ratingsCollector 0V DC (ground)

Shield Internally connected to filament

Grid +150V DC to ground

Filament +30V DC to ground

Filament volts AC 4.0 V

Filament current AC 3.5A (1 mA grid current)

Absolute maximum filament volts AC 6.0V

Absolute maximum filament current AC 6.0A

Absolute maximum filament temperature 1400°C

n For both grid and filament leads, one is positive and the other is ground

– It does not matter which lead is positive and which lead is ground

n All four bottom leads are in a single line

n Pin-out pattern is the same industry-wide

UHV and HV series


219

Vacuum measurementGlass envelope ionization gauge tubes



Vacuum

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Several of the Caburn-MDC tubes will directly interchangewith models of various manufac turers as noted in the crossreference table.

While tubes may have identical electrical specificationswith tubes from other manufacturers not listed, pin-outdimensions may vary.


Replacement for Replacement for Replacement forDescription Granville-Phillips Perkin-Elmer Varian

DN16CF Nominal size 274020 – –

DN40CF Nominal size 274008 605-7152 571-K2471-303

Pyrex® with graded seal, 19.1 tube 274002 – –

Pyrex® with graded seal, 25.4 tube 274005 – –

Kovar® with graded seal, 19.1 tube 274003 605-7000 571-K2471-305

Kovar® with graded seal, 25.4 tube 274006 – 571-K2471-302

Caburn-MDCReference

IGT-075-D

IGT-100-D

IGT-075-P

IGT-100-P

IGT-075-K

IGT-100-K

Caburn-MDCpartnumber

432023

432026

432021

432024

432022

432025

nominal127

86nominal

70 ODflange on25.4 ODtube

83nominal

nominal11434 OD

flange on19.1 ODtube

Featuresn UHV compatible

n CF flange

CF Flange


DN16CF 19.1 tube with DN16CF flange 0.2

DN40CF 25.4 tube with DN40CF flange 0.2

Reference

IGT-075-D

IGT-100-D

Partnumber

432023

432026

Method of Wtconnection Description kg

Pyrex® tube

19.1 19.1 tube 0.2

25.4 25.4 tube 0.2

Kovar® sleeve

19.1 19.1 tube 0.2

25.4 25.4 tube 0.2

Reference

IGT-075-P

IGT-100-P

IGT-075-K

IGT-100-K

Partnumber

432021

432024

432022

432025

45

19.1 OD

45

86nominal

114nominal

114nominal

25.4 OD

83nominal

Featuresn HV compatible

n Pyrex® tube or Kovar®

sleeve

Tubulated

220 Caburn-MDC Europe Limited Telephone +44 (0)870 428 7646 www.caburn.co.uk

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