2848
TRANSCRIPT
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f$ : 284% - 1986
Indian Standard
SPECIFICATION FOR INDUSTRTAL PLATINUM RESISTANCE THERMOMETER SENSORS
( First Revision )
Industrial Process Measurement and Control Sectional Committee, ETDC 67
Chairman
PROP J. K. Caounnua~ Jadavpur University, Calcutta
Members Refrescnting
SHRI ABHIJIT DE Sett and De, Calcutta SHRI A~ITAVA SENWPTA M. N. Dastur & Co Pvt Ltd, Calcutta
SEW ACHINTYA KUMER BISWAS ( Alternate ) SERI R. S. ARORA Dire;too; ,fteeneral of Supplies and Disposals,
SHRI G. BALARAM Indian Oil ?Zorporation, New Delhi SERI S. P. MATEUI~ (Alternate )
SERI G. BALASUBRAL~ANIAN Metallurgical and Engineering Consultants India Ltd, Ranchi
SHRI S. K. MlTuA (&tern&) SHRI K. R. BANERJEE Instrumentation Ltd, Kota
SHRI V. S. RA~ADAS ( Alternate ) SHRI J. K. CEATTERJEE Durgapur Steel Plant ( SAIL ), Durgapur SHRI D. P. GOEL Central Scientific Instruments Organization,
SHRI A. N. AQARWAL ( Alternate) Chandigarh
SHRI R. K. GOLIYA Udayraj and Sons, Bombay SERI P. C. G~LIYA ( Alternate )
SHRI G. L. KHANDUJA SHRI P. K. KRISIINAMURTHI
Electronics Corporation of India Ltd, Hyderbad lnstitute for Design of Electrical Measuring
Instruments, Bombay DR K. RA~ANI ( Alternate )
SHRI B. MUEHOPADHYA SHRI N. NARAYANA RAO
SHRI D. R. DHIMAN ( Alternate )
National Test House, Calcutta Controllerate of Inspection of Electronics,
Baogalore
( Continued on bag.4 2 )
0 Copyright 1987
BUREAU OF INDIAN STANDARDS
This publication is protected under the Indian CopVright Act ( XIV of 1957 ) and reproduction in whole or in part by any means except with written permission of the publisher shall be deemed to be an infringement of copyright under the said Act.
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( Continued from page 1 )
Members
SHRI B. PYNE
SHRI A. GHOSH ( Alternate ) SHRI D. V. S. RAJU
SHRI M. ANAHD ( Alternate ) SHRI S. RAMANATHAN
SHRI V. S. RAMDASS SHRI RAMDAS KISSENDAS
SHRI S. K. SHARMA ( Alternate ) DR N. J. RAO
DR S. K. ACIARWAL (Alternate ) SHRI A. RAVI PRASAD
SHRI N. SRIRAMAN ( Alternate ) SHRI K. P. SHARMA
Cdlcutta Electric Supply Corporation ( I) Ltd, Calcutta
ELICO Pvt Ltd, Hyderabad
Indian Drugs & Pharmaceutics Ltd, Virbhadra, Rishikesh
Oil & Natural Gas Commission, Dehra Dun Indian Petrochemicals Corporation Ltd, Vadodara
Institute of Paper Technology, Saharanpur
Beacon Rotork Controls Ltd, Madras
Project and Development India Ltd, Bihar . . \ SHRI V. N. SRIVASTAVA ( Alternare )
SHRI M. S. SHETTY Tata Consulting Engineers, Bangalore SHRI K. G. SRINIVASAN ( Alternate)
SHRI CH. SURENDER Department of Atomic Energy, Bombay SHRI S. RAMAKRISHNAN ( Alternate j
SERI S. P.SURI National Physical Laboratory, New Delhi DR A. F. CHHAPGAR ( Alternate )
SHRI K. K. TANEJA Directorate General of Technical Development, New Delhi
SHRI MOHANJEET SIN~H ( Alternate ) SERI M. G. TOSHNIWAL Toshniwal Industries Pvt Ltd, Ajmer
SHRI S. C. MAHESHWARI ( Alternate ) SHRI 1. UDANI Procorn Engineers, Calcutta
S&I N. BANDYOPADHYAY ( Alternate ) - SHRI A. K. VERMA Engineers India Ltd, New Delhi
SEIRI R. RHANOT ( Alternate ) SHRI H. C. VERMA Associated Instrument Manufacturers ( I ) Pvt Ltd,
SHRI M. D. NAIR SHRI S. P. SAOHDEV,
Director ( Elec tech
New Delhi ( Alternate )
Director General, BIS ( Ex-officio Member ) )
Secsetav SHRI B. K. MAHATA
Joint Director ( Elec tech ), BIS
2
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IS : 2848 - 1986
Indian Standard SPECIFICATION FOR INDUSTRIAL PLATINUM
RESISTANCE THERMOMETER
(First Revision)
0. FOREWORD
SENSORS
0.1 This Indian Standard ( First Revision ) was adopted by the Indian Standards Institution on 19 December 1986, after the draft finalizedby the Industrial Process Measurement and Control Sectional Committee had been approved by the Electrotechnical Division Council.
0.2 This standard was first published in 1965. This standard is revised to bring it in line with IEC Publication 751 and also to incorporate modified test methods and modifications in temperature/resistance relationship.
0.3 In the preparation of this revised standard, assistance has been deri- ved from IEC Publication 751-1983 Industrial Platinum Resistance Ther- mometer Sensors issued by International Electrotechnical Commission.
0.4 For the purpose of deciding, whether a particular requirement of this standard is complied with, the final value, observed or calculated, expres- sing the result of a test or analysis, shall be rounded off in accordance with IS : 2-1960*. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.
1. SCOPE
1.1 This standard specifies requirements and test methods for industrial platinum resistance thermometer sensors whose electrical resistance is a defined function of temperature. The standard covers thermometers suitable for all or part of the temperature range -200ยฐC to 850% with two tolerance classes. It is primarily concerned with sheathed ele- ments suitable for immersion in the medium whose temperature is to be measured.
*Rules for rounding off numerical values ( reuised ).
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IS : 2848 - 1986
2. TERMINOLOGY
2.0 For the purpose of this standard, the following definitions shall apply.
2.1 Ballast Resistor - A resistor, commonly having a negligible change of resistance with temperature, used in conjunction with the platinum resistor to bring the terminal resistance of the element within specified limits.
2.2 Fundamental Interval - The resistance change of a resistance ele- ment over the temperature range 0ยฐC to 100ยฐC.
2.3 Platinum Resistance Thermometer Sensor - A temperature- responsive device consisting of a sensing resistor within a protective sheath, internal connecting wires and external terminals to permit connec- tion of electrical measurement devices. Mounting means or connection heads may be included. Typical constructions are shown in Fig. 1.
NOTE 1 - This resistance thermometer sensor is referred to as a thermometer in subsequent clauses of this standard.
NOTE 2 -- This definition excludes any separable pocket or well provided with the thermometer.
TERMINALS BLOCK RESISTOR SHEATH
FIG. 1 TYPICAL CONSTRUCTION OF RESISTANCE THERMOMETER SENSOR
2.4 Sealed Element - An element suitable for pressure tight immersion in a vessel without further protection.
2.5 Tolerance - For the purpose of this standard the tolerance of a resistance thermometer is the maximum allowable deviation expressed in degrees Celsius from the nominal resistance temperature relationship such as given in Table 1.
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fS t 2sia - 1986
3. CONSTRUCTION
3.1 The conductor should be wound such that the method of supports shall avoid strain in the element both during fabrication and use.
3.2 The element shall be constructed so that no voltage is generated with- in them.
4. RESISTANCE CHARACTERISTICS
4.1 Temperature/Resistance Relationships - The temperaturelresi- stance relationships used in this standard are as follows:
i) for the range - 200ยฐC to 0ยฐC:
Rt = R, [ 1 + At + Btl + C ( t - 100 )ts ]
ii) for the range of 0ยฐC to 850ยฐC: Rt = R,, ( 1 + At + Bts )
For the quality of platinum commonly used for industrial resistance thermometers the values of the constants in these equations are:
3.908 02 x 10-3 โC-1 B^ : - 5.802 x IO-โ โC-a c= - 4.273 50 x 10-12 โC-4
For resistance thermometers satisfying the above relationship the temperature coefficient:
CI = 0.003 850 โC-l
alpha is defined as follows: R 100 - RO
a = 100 x R,- โC-1
where RI00 is resistance at IOOโC and R, resistance at 0ยฐC.
These equations are listed as the basis for the temperature/resistance tables of this standard and are not intended to be used for calibration of individual thermometers.
Values of temperature in this standard are in the International Prac- tical Temperature Scale of 1968 ( IPTS-68 ).
NOTE - Unless specified by the manufacturer the resistance values defined by the above equations do not include resistance of the leads between the sensing resistor and terminations.
4.2 Resistance Values - Most thermometers are constructed to have a nominal resistance of lOOn or 1OQ at 0ยฐC. The preferred value is lOO!Z The 1OQ is built with heavier wire for more reliable service above 600ยฐC.
Values of resistance using the equations of 4.1 are given in Table 1.
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TABLE 1 TEMPERATURE/RESISTANCE RELATIONSHIP g
EIPY-68 - -200 -150 -180 -170 -160 - 150 - 140 -130 -120
o\ -110 - 100
-90 -80 -70 -60 -50 -40 -30 -20 -10
0
tl
:!I 30 40 50 60 70
I_
. . ( Clause 4.3.1 )
g A.
R (0) = 100'00 A-2 a = 0โ003 85OโC-1 0, I
5: 9 10
I โC
EIPT-6% z -
0 1 2 3 4 5 6 7 8
18.49 22.%0 27.08 31.32 35.53 39.71
21โ94 21โ51 26โ23 25โ80 30โ47 30.05 34โ69 34.27
43.87 48.00 52โ11 56.19 60.25 64-30 68โ33 72.33 76.33 80.3 i 84โ27 88โ22 92โ16 96โ09
100โ00
22โ37 26โ65 30โ90 35.11 39โ30 43โ45 47.59 51โ70 55โ7% 59.85 63.90 67.92 71โ93 75.93 79โ91 83.88 87โ83 91.77 95.69 99.61
38โ8% 43โ04 47.1% 51.29 55โ3%
5693::: 67.52 71.53 75โ53 79โ5 1 83โ48 87โ43 91.37 95โ30 99โ22
38โ46 42โ63 46.76 50โ8% 54.97 59โ04 63.09 67.12 71โ13 75.13 79.11 83.0% 87โ04 90.9% 94โ91 98.83
21โ0% 20โ63 25.37 24โ94 29โ63 29.20 33 85 33โ43 38 04 37โ63 42.2 1 41โ79 46โ35 45โ94 50โ47 50โ06 54โ56 54โ15 58โ63 58โ22 62.68 62.2% 66โ72 66โ31 70.73 70โ33 74โ73 74โ33 78.72 78โ32 82โ69 82.29 86โ64 86.25 90โ59 90โ19 94.52 94โ12 9%,44 98.04
20โ22 19โ79 19.36 24.52 24 09 23.66 28โ7% 2% 35 27.93 33.01 32.59 32โ16 37โ21 36.79 36.37 41โ3% 40โ96 40โ55 45โ52 45.11 44.70 49โ64 49โ23 48โ82 53โ74 53โ33 52.92 57โ82 57.41 57.00 61โ87 61.47 61โ06 65โ91 65โ51 65.11 69.93 69โ13 73.93 z:: 73.13 77โ92 77โ52 77.13 81โ89 81โ50 81.10 85โ85 85โ46 85.06 89.80 89.40 89.0 1 93โ73 93.34 92.95 97-65 97โ26 96.87
102โ34 102 73 103โ12 106โ24 106โ63 107.02 110โ12 110โ51 110.90 113'99 114โ38 114โ77 117.85 118โ24 118โ62 121โ70 122.09 122โ47
1 125โ54 125โ92 126โ31
18โ93 18โ49 23โ23 22.80 27โ50 27โ0% 31โ74 31โ32 35โ95 35.53 40โ13 39.71 44โ2% 43โ87 48โ41 48โ00 52.52 52โ11 56โ60 56โ 19 60โ66 60โ25 64.70 64โ30 68โ73 63.33 72โ73 72โ33 76โ73 76.33 80โ70 80โ31 84โ67 84.27 88โ62 88โ22 92.55 92.16 96.48 96โ09
103โ51 103โ90 107.40 107โ79
-200 - 190 -180 -170 - 160 -150 -140 -130 --12v -110 -100
-90 -%O
70 160 -50 -40 -30 -20 -10
0
100โ00 100.39 100โ7% 101โ17 101.56 101.95 103.90 104.29 104โ6% 105โ07 105โ46 105โ85 107.79 108โ1% 108.57 108โ96 109โ35 109โ73 111โ67 112โ66 112โ45 112โ83 113.22 113โ61 135โ54 115โ93 116โ31 116โ70 117โ08 117โ47 119โ40 119.7% 120โ16 120โ55 120โ93 121โ32 123โ24 123.62 124โ01 124โ39 124โ77 125โ16 127โ07 127โ45 127โ84 128โ22 128.60 128.9% 129โ37 129โ75 130โ13 130.51 130โ89
111โ2% 111โ67 115โ15 115โ54 119โ01 119โ40 122โ86 123โ24 126.69 127.07
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Ei 100 110 120 130 140 150 160 170 180 190
;z 220 230 240 250 260 270 280
-l 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460
130โ89 134โ70 138.50 142โ29 146.06 149.82 153.58 157โ31 161.04 164.76 168โ46 172โ16 175โ84 179.51 183.17 186.82 190.45 194-07 197.69 201.29 204โ86 208โ45 212โ02 215.57 219.12 222โ65 226.17
;E: 236.65 240.13 243.59 247 04 250.48 253โ90 237.32 260.72 264โ11 267โ49
131.27 135โ08 138.88 142โ66 146โ44 150โ20 153โ95 157.69 161.42 165โ13 168โ83 172โ53 176โ21 179โ88 183โ53 187.1% 190โ81 19444 198โ05 101.65 205.23 208.81 212โ37 215.93 219โ47 223โ00 226โ52 230.02 233โ52 237โ00 240โ47 243.93 247.3% 250โ82 254.24 257โ66
131.66 132โ04 135โ46 135โ84 139โ26 139โ64 143.04 143.42 146.81 147โ19 150โ57 150โ95 154.32 154-70 158โ06 158โ43 161โ79 162โ16 165.50 165โ87 169.20 169โ57 172.90 173โ26 176.57 176โ94 180.24 180.61 183.90 184.26 187.54 187โ91 191.18 191โ54 194โ80 195.16 198.41 198.77 202โ01 202โ36 205โ59 205.95 209โ 17 209.52 212.73 213.09 216 2% 216.64 219.82 220.1% 223.35 223.70 226โ87 227.22 230.37 230โ72 233.87 234โ22 237.35 237.70 240โ82 241.17 244โ2% 244โ62 247.73 248.07 251โ16 251.50 254.59 254.93 258.00 258โ31 261โ40 261.74 264โ79 265โ13 268.17 268โ50
132โ42 132โ80 136โ22 136โ60 140.02 140โ39 143โ80 144โ17 147โ57 147 94 151.33 151โ70 155โ07 155โ45 158.81 159โ1% 162.53 162โ90 166โ24 166โ61 169โ94 170-31 173.63 174โ00 177โ3 1 l&T97 184โ63 188โ27 191โ90 195โ52 199โ13 202โ72 206โ31 209.88 213โ44 2 16โ99 220โ53 224โ06 227โ57 231โ07 234โ56 238โ04 241โ51 244โ97 248โ41 2,i-85 255.27 253โ6%
177โ68 181โ34 181โ99 188โ63 192โ26 195โ88 199โ49 203โ08 206โ67 2 10.24 213โ80 217โ35 220.88 224.41 227.92 23!โ42 234โ91 238โ39 241โ86 245-3 1 248.76 252.19 255โ61 259.02 262.42 265โ80 269โ1%
262โ0% 265โ47 268โ84
2LO.95 211โ31 211โ66 214โ15 214.51 214.86 215.22 217-70 218 05 218.41 218โ76 221โ24 221.59 221โ94 222โ29 224-76 225.11 225.46 225.81 228.27 228โ62 228.97 229.32 231โ77 232โ12 232โ47 232,82 235.26 235.61 235โ96 236.31 238.74 239 09 239โ43 239โ78 242.20 242โ55 242โ90 243.24 245โ66 246.00 246โ35 246.69 249.10 249.45 249.79 250.13 252โ53 252โ88 253.22 253.56 255.95 256.29 256.64 256โ98 259.36 259.70 260โ04 260.38 262โ76 266โ14 269.5 I
Resistance-ohms
133โ18 133โ56 133.94 134.32 134โ70 136.98 137โ36 137.74 138โ12 138โ50 140โ77 141โ15 141โ53 141โ91 142โ29 144.55 144-93 145โ31 145โ68 146.06 148โ32 148โ70 149โ07 149โ45 149โ82 152โ08 152โ45 152โ83 153.20 153.58 155.82 156โ19 156โ57 156 94 157.31 159.55 159โ93 160.30 160โ67 161โ04 163.27 163.65 164โ02 16-1โ39 164โ76 166โ98 167.35 167โ72 168โ09 168.46 170โ68 171โ05 171โ42 17 1โ79 172.16 174โ37 174.74 175โ10 175โ47 17.5โ84 178โ04 181โ71 185.36 189โ00 192โ63 196.24 199โ95 203โ44 207.02 210โ59
178โ41 178.78 ii9.14 182โ07 182โ44 1%2โ%0 185โ72 186โ09 186โ45 189โ36 189โ72 190โ09 192โ99 193.35 193โ71 196โ60 196.96 197.33 200โ21 200.57 200โ93 203.80 204.16 204โ52 207.38 207.74 208.10
263.10 263.43 263.77 266.4% 266โ82 267.15 269.85 270โ19 270โ52
179.51 183โ 17 186โ82 190โ45 194.07 197โ69 201โ29 204โ88 208โ45 212โ02 215.57 219.12 222โ65 226โ17 229.67 233โ17 236โ65 240.13 243.59 247*&I 250โ4% 253โ90 257.32 260.72 26411 267โ49 270.86
80 90
100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 t; . . 420 430 g 440 $ 450 I 460
5 ( Continued ) 8
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TABLE 1 TEMPERATURE/RESISTANCE RELATIONSHIP - Contd . .
ki R (0) = 100*00 B cc = 0โ003 85OโcY1 s
"C EIPTr68 0 1 2 3 4 5 6 7 8 9
I
CI
โC 10 I EIPT-68 g
470 480 490 500 510 520 530 540 550
co 560 570 580 590
600 610 620 630 640 650 660 670 680 690 700 710 720 730 740 750
270โ86 271โ20 271.53 271โ87 272โ20 272โ54 272โ88 273โ21 273โ55 273โ88 274โ22 274โ22 274.55 274โ89 275.22 275.56 275โ89 276โ23 276โ56 276โ89 277.23 277โ56 277โ56 277โ90 278.23 278โ56 278โ90 279โ23 279โ56 279.90 280โ23 280.56 280โ90 280.90 281โ23 281โ56 281โ89 282โ23 282.56 282โ89 283.22 283โ55 283โ89 284.22 284.22 284โ54 284-88 285โ21 285โ54 285โ87 286โ21 286โ54 286.87 287โ20 287.53 287โ53 287โ86 290โ83 291โ16 294โ11 294.44 297.39 297.72 300 65 300โ98 303โ91 304โ23 307โ 15 307.47 310โ38 310.70
313โ59 313โ92 316โ80 317โ12 319โ99 320โ31 323.18 323โ49 326โ35 326โ66 329โ51 329.82 332โ66 332โ97 335โ79 336โ11 338โ92 339โ23 342.03 342โ34 345โ13 345โ44
288โ19 288.52 291โ49 291โ81 294โ77 295.10 298'04 298-37 301โ31 301.63 304โ56 304โ88 307โ79 308โ12 311โ02 311.34
288.85 292โ14 295.43 298.70 301โ96 305โ20 308โ44 311โ67
3 14โ24 314.56 3 14โ88 317โ44 317.76 3 18.08 320โ63 320โ95 321โ27 323.81 324.13 324โ45 326โ98 327โ30 327โ61 330โ14 330โ45 330โ77 333โ28 333โ60 333โ91 336โ42 336.73 337.04 339โ54 339โ85 340โ16 342โ65 342โ96 343.27 345โ75 346โ06 346.37
289.18 289โ51 292โ47 292โ80 295โ75 296โ08 299โ02 299โ35 302โ28 302โ61 305โ53 305โ85 308.76 309โ09 311โ99 312โ31
309.41 312โ63
315.20 315โ52 315โ84 318.46 318.72 319โ04 321.59 321โ91 322โ22 324.76 325โ08 325โ40 327โ93 328โ25 328.56 331โ08 331.40 331โ71 332โ03 332โ34 334โ23 334โ54 334โ85 335โ17 335โ48 337โ36 337.67 337โ98 338 29 338โ61 340.48 340โ79 341โ10 341โ41 341โ72 343โ58 343โ89 344 20 344.51 344โ82 346โ68 346โ99 347โ30 347.60 347โ91
290โ17 290โ50 293โ46 293โ79 296โ74 297.06 300.00 300.33 303โ26 303โ58 306โ50 306โ82 307.15 309โ73 310โ05 310.38 312โ95 313.27 3 13.59
316โ16 316โ48 319.36 319โ68 322โ54 322โ86 325.72 326โ03 328โ88 329.19
290.83 294โ 11
316โ80 3 19โ99 323โ18 326โ35 329โ51 332โ66
~Kz 342.03 345โ13 348.22
348โ22 348โ53 348โ84 349.15 349.45 349โ76 350.07 350.38 350.69 350.99 351.30 351โ30 351โ61 351.91 352.22 352โ53 352.83 353.14 353โ45 353โ75 354โ06 35437 354-37 354โ67 354โ98 355โ28 355โ59 355โ90 356.20 356โ51 356โ81 357โ12 357.42 357โ42 357.73 358โ03 358.34 358โ64 358โ95 359.25 359โ55 359โ86 360.16 360.47 360โ47 360โ77 361.07 361โ38 361.68 361โ98 362.29 362โ59 362โ89 363โ19 363.50
470 480 490 500 510 520 530 540 550 560 570 580 590
600 610 620 630 640 650 660 670 680 690 700 710 720 730 740 750
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770 780 790
800 810 820 830 840 850
-
363โ50 363โ80 364.10 364.40 364.71 365โ01 365.31 365โ61 365โ91 366โ22 366โ52 366โ82 367.12 367โ42 367โ72 368โ02 368โ32 368.63 368โ93 369โ23 369โ53 369โ83 370โ13 370โ43 370.73 371โ03 371.33 371.63 37 1โ93 372โ22 372.52 372โ82 373โ12 373โ42 373.72 374.02 374โ32 37461 374โ91 375.21
375โ51 375โ81 376โ10 376โ40 376.70 377.00 377โ29 378.48 378โ78 379.08 379.37 .379โ61 379.97 380.26 381โ45 381โ74 382โ04 382โ33 382โ63 382โ92 383โ22 384โ40 384โ69 384โ98 385โ28 385.57 385โ87 386โ16 387.34 387.63 387.92 388.21 388โ51 388.80 389โ09 390.26
377.59 377.89 378โ19 380โ56 380-85 381โ15 383โ51 383โ81 384.10 386โ45 386โ75 387.04 389โ39 389.68 389โ97
Resistance-ohms
366โ52 760 369โ53 770 372โ52 780 375โ51 790
378.48 38 1โ45 384โ40 387.34 390โ26
800 810 820 830 840 850
-
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IS :2848- 1986
4.3 Tolerances - The tolerance values of resistance thermometers are classified as follows:
Toblerance Class Tolerance
( โC 1 A 0.15 + 0.002 1 t 1 *
B 0.3 + 0.005 1 t 1
4.3.1 Thermometrs of 1OOQ nominal resistance value shall be classified according to degree of conformity with the values of Table 1. The toleran- ces are given in Table 2, Class A tolerances shall not be applicable to 1OOQ resistance thermometers at temperatures above 650ยฐC.
TABLE 2 TOLERANCES FOR 100 8 THERMOMETERS
TEMPERATURE
( โC ) -
- 200
- 100
0
100
200
300
400
500
600
650
700
800
850
Class A T Class B
(dzยฐC)
0โ55
0.35
0.15
0.35
0โ55
0โ75
0โ95
1โ15
1โ35
1.45
-
-
-
(fQ)
0โ24
0โ14
0.06
0โ13
0.20
0.27
0โ33
0.38
0โ43
0โ46
-
-
-
l- (ikโC) (&Q)
1โ3 0โ56
0โ8 0โ32
0โ3 0โ12
0.8 0โ30
1โ3 0โ48
1โ8 0โ64
2โ3 0โ79
2โ8 0โ93
3โ3 1โ06
3โ6 1โ13
3.8 1.17
4โ3 1โ28
4โ6 1โ34
* 1 t 1 = modulus of temperature in degrees Celsius without regard to sign.
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IS :2848- 1986
Fxo. 2 TOLERANCE VALUES AS A FUNCTION OF TEMPERATURE FOR 100 52 THERMOMETERS
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IS: 2848 - 1986
5. ELECTRICAL SPECIFICATIONS
5.1 Supply Frequency - Thermometers shall be constructed so that they are suitable for use in measuring systems using direct curreut alternating current at frequencies up to 500 Hz.
5.2 Connecting Wire Configuration - Thermometers may be construc- ted with a variety of internal connecting wire configurations. Identification and designation of the terminals is therefore essential. Figure 3 shows the preferred methods.
5.3 Thermometer Identification - Each thermometer shall be marked to indicate resistance, class, connecting wire configuration, and temperature range, for example:
Pt 100/A/3 -100/+200
lDENflFlCATlON RED WHITE RED RED WHITE
(MARKING OR COLOUR CODING 1
DIAGRAM
CODE
u u
Pt lOO/ /2 P1100/ 13
IDENTIFIC;PTION Efy:si BLUE
CODE PI lOO/ /LC Pt lOO/ /L
Fro. 3 CONNECTION CONFIGURATIONS
If more than one sensing resistor is enclosed in a single sheath, the manufacturer should provide appropriate identification.
5.4 Resistance Values for 10 ohm and 1 ohm. Fundamental Inter- val - When the maximum temperature to be measured exceeds 600ยฐC, elements of lO*OOO-ohm and 1 *OOO 0 ohm fundamental interval may be used. The resistance values of 10.000 ohm and 1.000 0 ohm fundamental interval elements shall be as given in Table 3 and 4 respectively. The tole- rances for the values given in Table 3 and 4 shall be agreed between the purchaser and the manufacturer.
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IS : 2848 . 1986
TABLE 3 RESISTANCE OF lO*OOO-OHM FUNDAMENTAL INTERVAL ELEMENT
( Clause 5.4 )
TEMPERATURE RESISTANCE TEMPERA- RESISTANCE T.QMPERA- TURE TURE
;;
ohm โC ohm
(2) (1) (2) ;:
-220 2โ315 200 45โ2 76 650 -200 4.422 250 50โ015 700 - 150 9,921 300 54โ680 750
RESISTANCE
ohm
(2)
85.24 89โ33 93.32
-100 15โ256 350 59โ276 800 97โ2 1 -50 20โ460 400 63.785 850 100โ0
0 25.575 450 68โ225 900 104โ8
50 30.613 500 72โ59 1 950 108โ5
100 35โ575 550 76โ882 1 000 112โ1 150 40โ463 600 81โ100 1 050 115โ6
TABLE 4 RESISTANCE OF 1'000 O-OHM FUNDAMENTAL INTERVAL ELEMENT
( Clause 5โ4 )
TEMFERATURE RESISTANCE TENPERA- RESISTANCE TEMPERA- RESISTANCE TURE TURE
OC ohm โC ohm
;:
ohm
(1) (2) (1) (2) (2) -220 0.231 5 200 4.527 6 650 8โ524 -200 0โ442 2 250 5โ001 5 700 8.933
-150 0โ992 1 300 5.468 0 750 9โ332
- 100 1.525 6 350 5โ926 8 800 9โ721
-50 2โ046 0 400 6โ378 5 850 10โ10 0 2โ557 5 450 6โ822 5 900 10โ48
50 3โ061 4 500 7.259 1 950 IO.85
100 3.557 5 550 7โ688 2 1 000 11โ21 150 4046 3 600 8.110 0 1 050 11โ56
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IS : 2848 - 1986
6. MARKING
6.1 The resistance thermometer element terminals or external leads shall be clearly and prominently numbered and a diagram provided showing the internal connections of the element. The diagram shall give the grade and the resistance at 0ยฐC of the element. The name or trade-mark of the manufacturer and the country of manufacture shall also be suitably indica- ted. Normal maximum correct rating shall also be specified and marked.
6.2 The platinum resistance thermometer element may also be marked with the Standard Mark.
NOTE - The use of the Standard Mark is governed by the provisions of the Bureau of Indian Standards Act 1986 and the Rules and Regulations made there- under. The Standard 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 whit h is devised and supervised by RIS and operated by the producer. Standard marked products are also continuously checked by BIS for conformity to that standard as a further safeguard. Details of conditions under which a licence for the use of the Standard Mark may be granted to manufacturers or producers, may be obtained from the Bureau of Indian Standards.
7. INFORMATION TO BE AVAILABLE FROM THE MANUFAC- TURER
7.1 Electrical Characโteristics - To enable an accurate alternating current measuring system to be designed, maximum values of the relevant electrical characteristics ( that is, thermometer capacitance, capacitance to earth, and inductance ) shall be available on request. These data shall bc for ambient temperature and for the maximum intended temperature of use.
7.2 Depth of Immersion
7.2.1 Calibration Immersion Depth - The manufacturer shall declare the calibration immersion depth used in the resistance tests.
7.2.2 Minimum Usable Depth of Immersion - The manufacturer shall declare the minimum usable depth of immersion as determined by the test.
7.3 Thermal Response Time - The manufacturer shall declare the thermal response time in seconds as measured by one of the methods.
7.4 Self-Heating - The manufacturer shall declare the self-heating effect of the thermometer in โC/mW as measured by the methods of 8.5.
7.5 Ohmic Resistance of Internal Connection Wires - The manu- facturer shall supply the value of resistance of internal connection wires in two-wire sensors.
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IS : i848 - 1986
The values of resistance of internal connection wires for other confi- gurations shall be made available on request.
8. TYPE TESTS
8.1 Following shall constitute the types tests:
a) Insulation resistance test ( 8.2 ),
b) Resistance accuracy test ( 8.3 ),
c) Thermal response time test ( 8.4 ),
d) Self heating tests ( 8.5 ),
e) Immersion error test ( 8.6 ),
f) Thermo-eletric effect test ( 867 ),
g) Limiting temperatures test ( 8.8 ),
h) Stability test ( 8.9 ),
j) Drop test ( for sealed elements only ) ( 8.10 ),
k) Vibration test ( for sealed elements only ) ( 8.11 ), and
m) Pressure test ( for sealed elements only ) ( 8.12 ).
8.2 Insulation Resistance Test
8.2.1 When the sensing resistor is mounted in its sheath the insulation resistance betweenโeach terminal and sheath shall be measured with a test voltage between 10 V and 100 V dc and under ambient conditions between 15ยฐC and 35ยฐC and at a relative humidity not exceeding 80 percent. The polarity of the test current shall be reversed. In all cases the insulation resistance shall be not less than 100 MQ, when the value has stabilized.
8.2.2 An additional test shall be carried out at a test voltage not exceed- ing 10 V d.c. with the thermometer at the rated rnaximum temperature. The insulation resistance between each terminal and the sheath shall be not less than that shown in Table 5.
TABLE 5 INSULATION RESISTANCE AT MAXIMUM TEMPERATURE
RATED MAXIWJM TEMPERATURE MINIIXUM: INSULATION RESISTANCE
( โC ) (Ma)
100 to 300 10
301 to 500 2
501 to 850 0.5
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IS : 2848 - 1986
8,3 Resistance Accuracy Test - The resistance calibration of the ther- mometer element shall be made with the element inserted at least to the calibration immersion depth stated by the manufacturer and with a direct current such that the electrical power dissipated in the element does not cause any temperature rise due to self heating in excess of 20 percent of the tolerance at temperature. Measurement shall be made as given in IS : 2806-1964*. The test shall be made at a sufficient number of points over the working range of the element to establish that the resistance throughout the range lies within the limits specified, the measurement at each point being made with the current both forward and reversed.
8.4 Thermal Response Time - The thermal response time T is the time required for a thermometer to react to a step change of temperature with a resistance change corresponding to a specified percentage of the step change. The response time for a 50 percent change ( T 0.5 ) shall be recorded. In addition the response times for a 10 percent ( T 0.1 ) and 90 percent (I 0.9) changes or other changes may be reeorded if requested.
The value for 63-2 percent change is not recommeded because of possible confusion with the time constant of a simple, single-order device. To some extent, all thermometers exhibit variations from a single-order response.
8.4.1 General Test Requirements - If the response time is measured by changing the temperature of the surrounding medium, the time for the temperature of the test medium to reach 50 percent of its value shall not exceed l/10 of TO.5.
If the response time is measured by plunging the thermometer into a medium of different temperature, the time for the thermometer to reach the final immersion depth shall not exceed l/l0 of T 0.5;
EXAMPLES OF TEST DEVICES ARE DESCRIBED IN APPENDIX A
The response time of the recording instrument shall not exceed l/5 of T 0.5. Each characteristic value within the test shall be calculated as a mean value of a at least three tests, each of which falls typically within f 10 percent of the mean value.
The usable cross-section of test channel is that part of the actual cross- section with substantially uniform temperature and velocity distribution. The thermometer to be tested shall be inserted into the centre of test channel with its axis in a plane perpendicular to the direction of flow. The width of the channel shall be equal to or more than ten times the diameter of the themometer.
*Methods of temperature measurement by electrical resistance thermometer.
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IS : 2848 - 1986
8.4.2 Test Conditions for Flowing Air - The velocity within the usable cross-section should be 3 & 0.3 m/s. The initial temperature shall be be- tween 10ยฐC and 30%. The value of the temperature step shall be more than 10% and less than 20ยฐC. The minimum immersion depth of the thermome- ter to be tested shall be equal to the sensitive length of the thermometer plus 15 times its diameter. Where the design immersion depth of a thermo- meter is less than the above mentioned value, the test should be performed at the designed immersion depth. This immersion depth shall be mentioned in the test report.
8.4.3 Test Conditions for Flowing Water - For response times less than 1 the test apparatus should be designed so that the water has no free surface in front of or behind the thermometer so as to avoid problems of air entrainment. The velocity V within the usable cross-section shall be 0.4 f 0.05 m/s. The initial temperature shall be within the limits of 5% and 30%. The temperature step shall be not more than 10ยฐC.
The final temperature of the water shall not vary by more than f 1 percent of the temperature step during the duration of the measurement.
The minimum immersion depth shall be equal to the sensitive length of the thermometer plus five times its diameter,
Where the designed immersion depth of a thermometer is less than above-mentioned value, the test should be performed at designed immer- sion depth. This immersion depth shall be mentioned in the test report.
8.5 Self-Heating - This test shall be carried out with the thermometer immersed to the declared calibration immersion depth in well-stirred water maintained at the ice point. Suitable apparatus for testing the thermometer immersed to the calibration immersion depth is described in Appendix B.
The steady-state resistance shall be measured with a current such that the power dissipation in the thermometer is not more than 0.1 mW.
In the case of the nominal 1OOQ resistance thermometer the steady- state resistance shall then be measured at the manufacturerโs stated maxi- mum rate current, or 10 mA, whichever is less. The equivalent figure for the nominal 1OsZ thermometer is SO mA. The temperature rise equivalent to the measured increase in resistance shall not exceed 0*3โC.
Nol!E - This test may not be appropriate for certain small thermometers.When the thermometer is operated in gases, additional information on the effect of self- heating should be avialable from the manufacturer if requested.
8.6 Immersion Error - Suitable apparatus for testing the thermometer immersed to the calibration immersion depth is detailed in Appendix C. The test shall made with a measuring current such that the electrical power dissipated in thermometer is not greater than 1.0 mW. The test shall
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IS : 2848 - 1986
consist of slowly decreasing the depth of immersion until the indicated temperature changes by O* 1 โC. The depth of immersion shall than the measured and described as a minimum usable depth of immersion.
8.7 Thermo-Electric Effect - The thermometer may be tested in apparatus shown in Appendix C or in similar equipment.
Their immersion shall be slowly varied between the calibration immersion depth and the maximum practical depth until the electromotive force across the terminals is at its maximum which shall not exceed 2PrV.
8.8 Limiting Temperatures - The thermometer shall be subjected to the upper and lower limits of its temperature range for a period of 250 h at each temperature. The thermometer shall be immersed to at least its declared calibration immersion depth If the lower limit is below the tem- perature of liquid nitrogen boiling at atmospheric pressure, the latter tem- perature may be used for this test. The temperature should be allowed to rest at room temperature for a few minutes between the tests.
As a result of these tests the resistance at 0ยฐC shall not have changed by more than the equivalent of 0*15โC for Class A and 0.30% for Class B thermometer. The thermometer shall also be tested to ensure continued compliance with the insulation resistance requirements.
NOTE - Certain thermometers to be used within improved performance at narrower ranges than their total capability should be tested over range of intended use as stated by the user.
8.9 Effect of Temperature Cycling - The thermometer shall be brought slowly to the upper limit of its temperature range, then exposed to air at. room temperature. It shall then be brought slowly to the lower limit of its temperature range then exposed to air at room temperature. At each limit the thermometer shall be immrrsed to at least its declared calibration immersion depth and shall be maintained at the temperature for sufficient time to reach equilibrium. This procedure shall be repeated ten times. As a result of this test the resistance at 0ยฐC shall not have changed by more than the equivalent of 0*15โC for Class A and 0*3@C for Class B thermo- meters. If the lower limit is below the temperature of liquid nitrogen boiling at atmospheric pressure, the latter temperature may be used for this test. The thermometer shall also be tested to ensure continued compliance with the insulation resistance requirements of 8.2.1. .
NOTE - Certain thermometers to be used with improved performance at shorter ranges than their total capability should be tested over the range of intended use as stated by the user.
8.10 Drop Test - This test is intended to reveal any weakness of cons- truction. The thermometer, complete with head, if any, shall be held with its longitudinal axis horizontal and dropped ten times from a height of 250 mm on to a 6 mm thick steel plate on a rigid floor.
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The thermometer shall be inspected for mechanical damage. It shall also be tested to ensure continued compliance with the insulation resistance requirements and the maintenance of electrical continuity.
8.11 Vibration Test - This test should be conducted if possible with the thermometer mounted in the same manner as that in which it is to be used.
The mounting means shall be rigidly attached to the vibrator and the thermometer shall be vibrated over the frequency range of IOHz to 50OHz with a forcing acceleration of 20 m/s2 to 30 m/G peak-to-peak. The fre- quency range shall be swept at a rate of one octave per minute for a total period of 150 h.
The vibrations shall be applied to the thermometer in axial and trans- verse directions each for one half of the total period. The frequency and nature of any reasonances shall be noted. The electrical continuity shall be monitored continuously. At the conclusions of this test the thermometer shall be tested to ensure continued compliance with the insulation resistant requirements of 8.2.1. The thermometer shall also be tested to verify that the resistance at the ice point shall not have changed by more than the equivalent of 0*05โC.
8.12 Pressure Test ( for Sealed Elements Only )- The element shall be tested in a hydraulic test chamber containing water and ice in equili- brium and connected electrically to an approp_riate indicator. The pressure of the fluid in the chamber shall be raised to 3.5 MPa and shall be main- tained for I5 minutes.
The resistance of the element sha!l not very significantly from that appropriate to the equilibrium temperature corresponding to the pressure applied and when subsequently removed from the chamber, the element shall pass theโtests given in 8.2 and 8.3,
9. ROUTINE TESTS
9.1 Insulation Resistance Test - This test shall be carried out in accordance with 8.2.1 at the room temperature.
9.2 Resistance Tolerance - The resistance calibration of the thermo- meter shall be within the tolerance values specified in 4.3 when tested with a current such that the electrical power dessipated in the thermometer does not cause a rise of temperature due to self-heating in excess of l/5 the tole- rance value at the temperature.
The test for Class A thermometers shall be carried out at two or more temperatures suitably spaced over the stated working range and with the thermometer inserted in the test medium to at least the declared calibra- tion immersion dept ( see 7.2 ).
The test for Class B thermometers shall be carried out at one tempe- rature, normally the ice point.
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k_.__._--_
f&:2848-1986
APPENDIX A ( Clause 8.4.1 )
EXAMPLE OF TEST DEVICES FOR THERMAL RESPONSE TIME MEASUREMENTS
A-l. Device for Testing in Air
A-l.1 Air is blown through a diffuser and a wire mesh into the test channel having a rectangular cross-section by means of a fan. The thermometer is mounted in the centre of the test channel with the logitudinal axis of the thermometer normal to the direction of air flow.
In front of the thermometer a heatable wire grid is mounted. The temperature step is generated by switching on and off an electrical current through this wire grid.
The 50 percent time of the temperature step generated with the abovementioned wire grid with a wire diameter of 2 x 10-s mm at a velocity of 1 m/s is 15 m/s for example. For testing thermometers with a diameter smaller than 2 mm, the distance between the grid wires should be about 0.5 mm and for thicker thermometers 1 mm to l-5 mm.
CLAMPING DEVICE
FIG. 4 TEST DEVICE FOR TESTING IN AIR
A-2. METHOD OF MEASURING RESPONSE TIME IN WATER OR OTHER LIQUIDS
A-2.1 A cylindrical vessel with a diameter of 300 mm or more and a height of 200 mm or more is filled with the test liquid. The liquid is forced into rotation either by rotating the vessel or by a rotating drum inserted into the centre of the vessel from above.
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-ll--..-..-.__--._ .-_ ..-.
IS : 2848 - 1986
The test liquid is heated to a temperature approximately 104 above ambient. This heating can be effected by various means such as by heating elements placed on outer surface of the vessel.
The thermometer is fixed on the end of a pivoted arm. When the temperature of the liquid and the thermometer is lowered rapidly into the liquid.
The velocity of flow can be controlled by the rotary speed of the liquid and the radial position of the thermometer.
iERMOMETER
\ TO VARIABLE SPEED DRIVE
7
1
l-7 ,ROTATING ORUM
PIVOT POINT
INFRA- VESSEL
TO VARIABLE SPEED
FIG. 5 TEST Dmam FOR SIMPLIFIED TEST IN
21
DRIVE
WATER OR OTHER LIQUIDS
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IS : 2848 - 1986
APPENDIX B ( Clause 8.5 )
MEASUREMENT OF SELF-HEATING
B-l. An apparatus suitable for measuring self-heating effect is shown in Fig. 6. This consists of a large Dewar flask in which water at the ice point may be circulated past the element under test. Two tubes of brass or other non-corrosive material are suitably supported on opposite sides of the flask over a layer of small lump ice. The remainder of the space is packed with finely crushed ice up to the level of the top of the tubes water at approxi- mately 0ยฐC is poured into the flask until the level is approximately 6 mm above the level of the tubes. A well-insulated cover is placed on top of the Dewar flask with suitable holes to pass the shaft of stirrer paddle situated in one tube and the thermometer element situated in the other tube. The direction of rotation of the stirrer should be such that the watee is driven
COPPER MESH_, /
/! /RESISTANCE ELEMENT STlR,;R ,M~ ,~
DISTILLED WATER AIR SATURATED AT 0 โc
/ / I ~-INSULATING cowR
15LlTRE DEWAR FLASK
FINELV CRUSHED ICE
COPPER MESH
FIG. 6 APPARATUS FOR MEASURING SELF-HEATING
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down through the small lump ice before passing up the tube containing the element. Non-corrosive metal gauge across the bottom of the two tubes and round the top of the stirrer well will prevent the circulation of lumps of ice from interfering with the stirring action. Adequate circulation of the water is shown by the pressure of a pronounced vortex in the stirrer well.
APPENDIX C ( Clauses 8.6 and 8.7 )
DETERMINATION OF IMMERSION ERROR AND THERMO-ELECTRIC EFFECT
C-l. The apparatus ( see Fig. 7 ) should consist of a container with a base of phenolio-resin, or other suitable material of similar thermal characteris- tics ( conductivity not more than 2.5 W/mโ% ). The base should be appro- ximately 12 mm thick. The detecting end of element under test should
PLASTK CON1
-ICE WATER
,PCASTIC BAS
.HYPSOMETEA
;AtNER
IE
FIG. 7 SCHEMATIC TEST APPARATUS FOR DETERMINATION OF IMMLRSION ERROR AND THERMO-ELECTRIC EFFECT
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- _.
pass through the centre of the base of the container into a steam hypsome- ter. There should be means of ad.justing and measuring the depth of imer- sion of the element in the hypsometer.
C-2. The container should contain ice water to a depth of not less than 50 mm and when the element is in position the hold through which it passes should be sealed to prevent water leakage.
C-3. The associated measuring apparatus should be capable of detecting a temperature, change of 0.1 deg C or O-04 ohm. The current passed through the element while measurements are being made should not exceed 2 mA.
24