ti06b00a01-01e

TechnicalInformation

Yokogawa Electric Corporation

Resistance Thermometer Sensor andThermocouple Data Collection

TI 6B0A1-01E© Copyright Oct. 1990 (YK)3rd Edition: May 2003 (YG)

IntroductionResistance thermometer sensors (RTSs) and thermocouples are the temperature sensors most widely used in industrialtemperature measurement. They have the advantages of simple construction and ease of use, making for convenience inmeasurement.However, if correct application methods based on the proper standards are not followed, highly accurate measurementscannot be expected.This document is a compendium of the basic data relating to resistance thermometer sensors and thermocouples. *Thissecond edition reflects IEC and JIS revisions (thermocouples) of July 1995. We hope that this document will aid you incomparing the various underlying standards from an international viewpoint, and in deciding which standards to follow.This document also provides information on vital parameters such as operating temperature ranges and tolerances.

Contents

1. RESISTANCE THERMOMETER SENSORS .................................................................................................. 11.1 Overview of the IEC Revisions ........................................................................................................................................ 1

1.2 Overview of the JIS Revisions .......................................................................................................................................... 1

1.3 Types of Resistance Thermometer Sensors ...................................................................................................................... 3

1.4 Tolerances vs. Temperature .............................................................................................................................................. 3

1.5 Temperature/Resistance relationships Values in Various Nations ................................................................................... 4

1.6 Copper Resistance Thermometer Sensors ......................................................................................................................... 5

2. THERMOCOUPLES ............................................................................................................................................ 62.1 Overview of the JIS '95 Revisions .................................................................................................................................... 6

2.2 Types of Thermocouples ................................................................................................................................................... 7

2.3 Thermal EMF Characteristics ......................................................................................................................................... 10

2.4 Tolerance ......................................................................................................................................................................... 11

2.5 Themocouple Electrical Characteristics .......................................................................................................................... 11

2.6 Thermocouple operating Limits ...................................................................................................................................... 12

2.7 Thermocouple Leadwire Resistances .............................................................................................................................. 13

3. MINERAL INSULATED THERMOCOUPLES ............................................................................................. 143.1 Construction ..................................................................................................................................................................... 14

3.2 Tolerances ........................................................................................................................................................................ 15

3.3 Codes and Normal Operating Limits .............................................................................................................................. 16

3.4 Electrical Characteristics ................................................................................................................................................. 17

(Insulation Resistance, Thermocouple Leadwire Resistance) ........................................................................................ 17

4. EXTENTION AND COMPENSATING CABLE ............................................................................................ 18

5. INTERNATIONAL TEMPERATURE SCALE .............................................................................................. 205.1 International Temperature Scale Plan ............................................................................................................................. 20

5.2 Essentials of the 1990 International Temperature Scale (ITS-90) ................................................................................. 21

5.3 Influence of ITS-90 on Industrial Thermometers ........................................................................................................... 22

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APPENDIX A RESISTANCE THERMOMETER SENSORSAPPENDIX TABLE A1 PT100 REFERENCE RESISTANCE TABLE .......................................................................... 24

APPENDIX TABLE A2 JPT100 REFERENCE RESISTANCE TABLE ........................................................................ 26

APPENDIX TABLE A3 RT50 REFERENCE RESISTANCE TABLE ........................................................................... 28

APPENDIX TABLE A4 PT100 REFERENCE RESISTANCE TABLE .......................................................................... 30

APPENDIX TABLE A5 INTERPOLATION EQUATION FOR PT100 REFERENCE RESISTANCE ........................ 32

APPENDIX TABLE A6 INTERPOLATION EQUATION FOR JPT100 REFERENCE RESISTANCE....................... 32

APPENDIX B THERMOCOUPLESAPPENDIX TABLE B1 TYPE B THERMOCOUPLE THERMAL E.M.F. TABLE...................................................... 33

APPENDIX TABLE B2 TYPE R THERMOCOUPLE THERMAL E.M.F. TABLE...................................................... 37

APPENDIX TABLE B3 TYPE S THERMOCOUPLE THERMAL E.M.F. TABLE ...................................................... 41

APPENDIX TABLE B4 TYPE N THERMOCOUPLE THERMAL E.M.F. TABLE ..................................................... 45

APPENDIX TABLE B5 TYPE K THERMOCOUPLE THERMAL E.M.F. TABLE ..................................................... 48

APPENDIX TABLE B6 TYPE E THERMOCOUPLE THERMAL E.M.F. TABLE ...................................................... 52

APPENDIX TABLE B7 TYPE J THERMOCOUPLE THERMAL E.M.F. TABLE ....................................................... 55

APPENDIX TABLE B8 TYPE T THERMOCOUPLE THERMAL E.M.F. TABLE ...................................................... 58

APPENDIX TABLE B9 INTERPOLATION EQUATION OF REFERENCE THERMAL E.M.F. of JIS'95

(JIS C1602-1995) ....................................................................................................................... 60

APPENDIX TABLE B10 TYPE B THERMOCOUPLE THERMAL E.M.F. TABLE...................................................... 68

APPENDIX TABLE B11 TYPE R THERMOCOUPLE THERMAL E.M.F. TABLE...................................................... 72

APPENDIX TABLE B12 TYPE S THERMOCOUPLE THERMAL E.M.F. TABLE ...................................................... 76

APPENDIX TABLE B13 TYPE K THERMOCOUPLE THERMAL E.M.F. TABLE ..................................................... 80

APPENDIX TABLE B14 TYPE E THERMOCOUPLE THERMAL E.M.F. TABLE ...................................................... 84

APPENDIX TABLE B15 TYPE J THERMOCOUPLE THERMAL E.M.F. TABLE ....................................................... 87

APPENDIX TABLE B16 TYPE T THERMOCOUPLE THERMAL E.M.F. TABLE ...................................................... 90

APPENDIX TABLE B17. INTERPOLATION EQUATION OF REFERENCE THERMAL E.M.F. of JIS'81

(JIS C1602-1981, abolished after July 1995) ............................................................................ 92

APPENDIX TABLE B18 Cu-CuNi THERMOCOUPLE THERMAL E.M.F. TABLE (DIN 43710 TYPE U) ............... 96

APPENDIX TABLE B19 Fe-CuNi THERMOCOUPLE THERMAL E.M.F. TABLE (DIN 43710 TYPE L) ................ 98

APPENDIX TABLE B20 W (W5Re/W26Re) THERMOCOUPLE REFERENCE THERMAL E.M.F. TABLE

(ASTM E988) ........................................................................................................................... 101

APPENDIX TABLE B21 KP/Au•Fe THERMOCOUPLE REFERENCE THERMAL E.M.F. TABLE ......................... 105

APPENDIX TABLE B22 TABLE OF THERMOCOUPLE REFERENCE THERMAL E.M.F. PRACTICED IN

TABLES OTHER THAN THOSE DEFINED IN JIS. ........................................................... 106

1TI 6B0A1-01E

1. Resistance Thermometer SensorsResistance thermometer sensors (RTSs) are temperature sensors that make use of thephysical property where electrical resistance in metal increases proportionally with anincrease in temperature. Since platinum RTSs can be expected to provide the mostaccurate temperature measurement of all industrial temperature sensors, they are widelyused, especially in conditions near room temperature.

One of the requirements for an industrial thermometer sensor is that its performance andcharacteristics be guaranteed by a standard. Platinum RTSs have been standardizedunder JIS C 1604 ("Resistance Thermometer Sensors") and JIS C 1606 ("SheathedResistance Thermometer Sensors") in Japan, and standardized under IEC-751 ("Indus-trial Platinum Resistance Thermometer Sensors") abroad. These standards were recentlyrevised one after another. This document explains the revisions and summarizes theessential data based on the new standards.

1.1 Overview of the IEC RevisionsIEC-751 was revised in July, 1995. The major change in this revision is to revisereference resistance in accordance with the temperatures of the 1990 InternationalTemperature Scale (ITS-90). ITS-90 has adopted as the new International TemperatureScale since January 1, 1990 (Refer to 5. International Temperature Scale of thisdocument). IEC had started study to revise IEC-751 reference resistance immediatelyafter ITS-90 adoption, and finally accomplished.

1.2 Overview of the JIS RevisionsResistance thermometer sensors JIS was revised in February, 1997. This revision madeJIS C 1604 completely conform to IEC-751.

The major changes are as follows.

(1) JIS for Resistance thermometer sensors is uniformed to JIS C 1604 (Resistancethermometer sensors) and JIS C 1606 (Sheathed resistance thermometer sensors) isabolished.

(2) Reference resistance table is revised to conform to IEC standard. In the new JIS,reference resistance table is revised in accordance with the temperatures of the 1990International Temperature Scale (ITS-90) which is adopted in IEC standard. As forthe new resistance reference resistance table, refer to Table A5 Resistance table atthe end of this document.Figure 1 shows the difference between reference resistance values of JIS'89 Pt100and those of JIS'95 Pt100. For example, when the measured temperature is 100˚C,the difference is +0.027˚C, at 300˚C, it is +0.083˚C and at 500˚C, 0.242˚C. Thisdifference is bigger than the temperature difference between the old InternationalTemperature Scale (IPTS-68) and ITS-90 (Refer to 5.3 Influence of ITS-90 onIndustrial Thermometers). Comparing the temperature differences to the tolerancesat measured value 500˚C, it is about one fifth of the tolerance in class A, and lessthan one tenth in class B, so their influence can be ignored on a practical industrialuse level. However, in using digital device which resolution is 0.1˚C or less thanthat, the influence cannot be ignored.

(3) JPt100, which has used for many years in Japan, is abolished.JPt100, which has unique reference resistance values of Japan, is abolished in thenew JIS. With regard to JPt100, it was already announced that it would be abolishedin the future at the last time revision (January, 1989). However, considering the

TI 6B0A1-01E2

situation that they have been used for more than thirty years and many of them arestill in use, the 1989 reference resistance table remains in the guide. It is alsodescribed in the guide that the characteristics of JPt100 are almost the same as thoseof Pt100 so that the quality of supplement is guaranteed. This Technical Informationprovides reference resistance tables of abolished JPt100, JIS'89 Pt100 and JIS'9150Ω(Pt50) for reference.

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

0.000 50 100 150 200 250 300 350 400 450 500 550 600 650 700

t/˚C

∆t/˚C

3TI 6B0A1-01E

1.3 Types of Resistance Thermometer SensorsThe types of RTSs specified in JIS C 1604 and JIS C 1606 are standardized, as shownin Table 2, according to the standard resistance element R100/R0 value, Class, ratedcurrent, operating temperature range, and lead wire system.

Table 1 Resistance Thermometer Sensors (JIS C 1604-1989, JIS C 1606-1989)

edoC eulav0R/001R ssalC tnerrucdetaRerutarepmetgnitarepO

egnarmetsyseriwdaeL

001tP 0583.1AssalCBssalC

Am1Am2*Am5

LMH

C˚001ot002-C˚053ot0C˚056ot0

*eriw-2eriw-3eriw-4

)001PJ( )6193.1(AssalCBssalC

Am1Am2*Am5

LMH

C˚001ot002-C˚053ot0C˚056ot0

*eriw-2eriw-3eriw-4

:etoN001taeulavecnatsiserehtsi001R.1 ° .C

001foeulavecnatsiserehtsi0R.2 Ω fota ° .C.deunitnocsidsisesehtnerapnimetinA.3

.AssalCniylppatonod*nahtiwdekramsmetI.4005+ot0siHegnarerutarepmetgnitareposSTRdehtaehS.5 ° .C

.sSTRdehtaehsotelbacilppatonsimetsyseriwdaeleriw-2ehT.6

1.4 Tolerances vs. TemperatureTolerances with respect to temperature must be within the ranges in Table 3 throughoutthe operating temperature ranges. Table 4 shows samples of tolerance versus measuredtemperature. If the measured temperature t °C in Table 3 includes a fractional valuebelow the decimal point, the tolerance range includes the smaller value. To avoid therisk of disputes in judgment as a result of exceeding measurement capability, thefollowing guidelines are used for rounding off the tolerances: In Class A the number ofvalid significant digits below the decimal point is two, rounded down from three. InClass B the number of valid significant digits below the decimal point is one, roundeddown from two.

Table 2:stinU °C

ssalC ecnareloT

AssalC ± )|t|200.0+51.0(

BssalC ± )|t|500.0+3.0(

Note 1: The error in the measured temperature of the resistance element is the measured temperaturesubtracted from the temperature computed from the resistance value displayed by the resistanceelement according to Appendix Table A1 ro Appendix Table A2.

Note 2: |t| is the absolute value of the measured temperature (°C), irrespective of the + or – sign.

Note 3: Although old JIS Class 0.15 has been discontinued, Yokogawa will sell it, but for the JPt100 only.Tolerance for old JIS Class 0.15 is + (0.15+0.0015 t), and applies over the temperature range of 0 to

+350 °C.

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Table 3:stinU °C

erutarepmetderusaeMecnareloT

AssalC BssalC

002- ± 55.0 ± 3.1

001- ± 53.0 ± 8.0

0 ± 51.0 ± 3.0

001 ± 53.0 ± 8.0

002 ± 55.0 ± 3.1

003 ± 57.0 ± 8.1

004 ± 59.0 ± 3.2

005 ± 51.1 ± 8.2

006 ± 53.1 ± 3.3

056 ± 54.1 ± 6.3

Note:1. The error in the measured temperature of the resistance element is the measured temperature subtracted

from the temperature computed from the resistance value displayed by the resistance element according toAppendix Table A1 ro Appendix Table A2.

2. |t| is the absolute value of the measured temperature (°C), irrespective of the + or – sign.3. Although old JIS Class 0.15 has been discontinued, Yokogawa will sell it, but for the JPt100 only.

Tolerance for old JIS Class 0.15 is + (0.15+0.0015 t), and applies over the temperature range of 0 to +350°C.

Table 4 Temperature/Resistance Characteristics of Resistance Thermometer Sensors(erutarepmeT ° )C 001tPJ98'SIJ 001tP,98'SIJ 001tP5991-157CEI

002- 41.71 94.81 25.81

001- 75.95 52.96 62.06

0 00.001 00.001 00.001

001 61.931 05.831 15.831

002 31.771 48.571 68.571

003 39.312 20.212 50.212

004 65.942 40.742 90.742

005 20.482 09.082 89.082

006 82.713 95.313 17.313

007 31.543 82.543

008 15.573 07.573

elbaTecnatsiseRdradnatS 6A,2AxidnappA 1AxidneppA 5A,4AxidneppA

:etoNdesivereblliw4061CSIJ,egnahcsihtotmrofnocoT.5991,yluJnidesiversawelbatecnatsiserdradnatS157CEI

.noos

1.5 Temperature/Resistance relationships Values in Various NationsTable 5 shows a comparison of resistance thermometer characteristics. IEC standardswere standardized in Pub 751 in 1983. Due to intensifying international influence, JISwas revised to accept these in January of 1989. Note that there are significant differ-ences between JPt100 and Pt100.

5TI 6B0A1-01E

1.6 Copper Resistance Thermometer SensorsThere are no standards for copper RTSs in JIS, and they have been little used in generalindustry, but they are found in rotating electrical equipment, primarily to measuretemperatures of coils, bearings, etc. The following shows the nominal resistances andthe standard resistance element Rt/Ro standardized in JEM 1252 (Japan ElectricalManufacturers’ Association) for RTSs in rotating electrical equipment.

Table 5 Nominal ResistancefoepyTecnatsiser

tnemele

lanimoNecnatsiser

dradnatSerutarepmet

DTRreppoC01 Ω 52 °C

52 Ω 0°C

Table 6 Standard Resistance Element Rt/Ro Copper Resistance Thermometer SensorserutarepmeT °C oR/tR erutarepmeT °C oR/tR

0 0000.1 09 5283.1

01 5240.1 001 0524.1

02 0580.1 011 5764.1

52 2601.1 021 0015.1

03 5721.1 031 5255.1

04 0071.1

05 5212.1

06 0552.1

07 5792.1

08 0043.1

TI 6B0A1-01E6

2. THERMOCOUPLESThermocouples sense temperatures based on the principle that an electrical current isgenerated when two different metals are combined in a closed circuit and subjected to atemperature difference; they are widely exploited in industry due to their simple con-struction and excellent reliability. There are many types of thermocouples in use.Those which are the most widely used, whose characteristics are understood, and whichhave demonstrated their reliability, have become the objects of standardization. Thisdocument deals primarily with those thermocouples standardized in the JIS, plus othertypically used thermocouples that have been field-proven in particular applications.

2.1 Overview of the JIS '95 RevisionsJIS standards related to thermocouples were revised as of July 1, 1995. The majorpurpose of this revision is to make these JIS standards conform to the internationalstandard IEC 584. Thermocouple codes, thermal EMF, and tolerance classes wererevised to match IEC584, so JIS standard data are consistent with the standards usedabroad now.

The major changes are "N thermocouple is newly stipulated" and "standard thermalEMFs revised". As shown in Figure 1, the difference between JIS'89 and JIS'95 thermalEMFs will have little effect on industrial temperature measurement.

Figure 1 Revised Value of Thermal EMF

7TI 6B0A1-01E

2.2 Types of ThermocouplesIn most cases, a thermocouple’s type is indicated by a code. Since the codes specifiedin JIS conform to the IEC standards, they are shared with other international standards,in particular with DIN (Germany) and ANSI (United States) [See Table 10]. Table 8shows the codes, component materials, operating limits, and other features of thermo-couples standardized in JIS. Table 9 shows representative non-JIS-standard-thermo-couples in practical use.

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Table 7 Thermocouple Codes, Component Materials, Normal Operating Limits, andOverheat Operating Limits (JIS C 1602-1981)

edoCdlOedoc

slairetamtnenopmoCssalC

tnemelEretemaid

)mm(

lamroNgnitarepo

(stimil ° )C

taehrevOgnitarepo

(stimil ° )CseitreporP

edis+ edis–

B –

%03sniatnoC.muidohR-munitalP

yollamuidohR

%6sniatnoC.muidohR-munitalP

yollamuidohR

2ssalC3ssalC

05.0 0051 0071

yrevsiFMElamrehTmoortallams.erutarepmet

nisecnereffidegraLscitsiretcarahc

.neessemitemossaemasehtesiwrehtO

.RepyT

R –

%31sniatnoC.muidohR.munitalP

yollamuidohR

munitalP

2ssalC

05.0 0041 0061

saelbatiuS.elbatsyreV.elpuocomrehtdradnats

evisorrocrofelbatiuS.stnemnorivne

,negordyhotevitisneSllamS.sropavlatem

yreV.FMElamreht.egnahcralucesthgils

eriwnoisnetxeegraL.rorre

S –

%01sniatnoC.muidohR.munitalP

yollamuidohR

munitalP 05.0 0041 0061

Nyliramirp,yollA,emorhC,lekciN

nociliSdna

yliramirp,yollAdna,lekciN

nociliS

1ssalC2ssalC3ssalC

56.0 058 009 noisorroctnellecxEsemitlareves(ecnatsiser

oN.)KepyTfotahtoteudnoitarenegrorre

.gniredroegnar-trohsdleifcitengaM

ylevitalerecneulfni.llams

00.1 059 0001

06.1 0501 0011

03.2 0011 0511

02.3 0021 0521

K ACyliramirp,yollA

dnalekciNemorhC

yliramirp,yollAlekciN

1ssalC2ssalC3ssalC

56.0 056 058.ytiraenilFMEdooGenisorrocrofelbatiuS

tnatsiseR.tnemnorivne.sropavlatemot

.egnahcralucesemoS

00.1 057 059

06.1 058 0501

03.2 009 0011

02.3 0001 0021

E CRCyliramirp,yollA

dnalekciNemorhC

yliramirp,yollAdnareppoC

lekciN

1ssalC2ssalC3ssalC

56.0 054 005

epyTnahttsocrewoL.FMElamrehtregral,K

emoS.citengam-noN.emitrevotfird

00.1 005 055

06.1 055 056

03.2 006 057

02.3 007 008

J CI norIyliramirp,yollA

dnareppoClekciN

1ssalC2ssalC3ssalC

56.0 004 005 ylriafhtiw,tsocwoL.FMElamrehtegral

.ytiraenilFMEdooGgnicuderrofelbatiuSegraL.stnemnorivne

elpmas-ot-elpmasnisnoitairav

.ytilauq,scitsiretcarahdtastfirD.ylisaestsuR

.serutarepmethgih

00.1 054 055

06.1 005 056

03.2 055 057

02.3 006 057

T CC reppoCyliramirp,yollA

dnareppoClekciN

1ssalC2ssalC3ssalC

23.0 002 052 dooghtiw,tsocwoLerutarepmet-wol

dooG.scitsiretcarahcrofelbatiuS,ytiraenil

.stnemnorivnegnicudereriwnoisnetxeegraL

.rorre

56.0 002 052

00.1 052 003

06.1 003 053

9TI 6B0A1-01E

Table 8 Non-JIS Thermocouples in practical Use

emaNslairetamtnenopmoC gnitarepO

erutarepmettaehrevOegnar

)(nitimil

seitreporPFMElamrehtdradnatS

ytirohtuadna,elbatedis+ edis-

-munitalPmuidohR

%02sniatnoC.muidohR

-ohR-munitalPyollamuid

%5sniatnoC.muidohR


0051ot003 °C0081( ° )C

.serutarepmethgihtaelbasU.FMElamrehtllamS

.RepyTsaemas,esiwrehtO22BelbaTxidneppA

%04sniatnoC.muidohR


%02sniatnoC.muidohR


0061ot0011 °C0081( ° )C

-netsgnuTmuinehR

%5sniatnoC.muidohR


%62sniatnoC.muidohR


0042ot0 °C0003( ° )C

gnicuderrofelbatiuS,sessagtreni,stnemnorivne

.eligarF.sagnegordyh

02BselbaTxidneppA48-889EMTSA

%3sniatnoC.muidohR


%52sniatnoC.muidohR

-ohR-munitalPyollamuid 22BelbaTxidneppA

48-889EMTSA

netsgnuT

%62sniatnoC.muidohR


lenitalP

,yollAyliramirp

,muidallaPdna,muitalP

dloG

,yollAdloGyliramirp

muidallaPdna

0011ot0 °C0031( ° )C

.noisarbaotecnatsiserhgiHehtylraenFMElamrehT.KepyTfotahtsaemas

SBN22BelbaTxidneppA.lov,hcraeseRfolanruoJ

80N.C86

/lemorhCnorI-dloG

,yollAyliramirp

dnalekciN0?4oemorhC

)lemorhC(

70.0sniatnoC.norI%elom

yollanorI-dloGK003ot1

ylevitalerFMElamrehT.wolebdnaK02taegral

.ytiraenilFMEdooG

034TPSMTSA12BelbaTxidneppA

TI 6B0A1-01E10

2.3 Thermal EMF CharacteristicsThe standard thermal EMFs of the various thermocouple types are shown in AppendixTables B1 through B19.

Because JIS C 1602-1995 was written to be consistent with the standards used in othercountries, particularly IEC, ANSI, etc., this is beneficial when importing and exporting.However, attention is required since the DIN standard adopts its own unique specifica-tions for Type U and Type L. Table 10 gives a list of the standard thermal EMFdocument selections for the individual national and international standards. Equationsfor interpolation of standard thermal EMFs are provided for reference at the end of thisdocument.

Table 9 Thermal EMF Document Selection List

cirenegelpuocomrehTeman

noitangixeddradnatselpuocomrehTFMElamrehtdradnatS

rebmuntnemucodskrameRepytdradnatS

SIJ CEI ISNA SB NID

03-6/muidohR-munitalP BEPYT 1B-elbaTxidceppA

munitalP/muidohR-munitalPREPYT 2B-elbaTxidneppA

SEPYT 3B-elbaTxidneppA

)N(lisiN/lisorhciN NEPYT 4B-elbaTxidneppA

lemulA/lemorhC KEPYT 5B-elbaTxidneppA

natnatsnoC-lemorhC EEPYT 6B-elbaTxidneppA

natnatsnoC-norI

JEPYT 7B-elbaTxidneppA

–LepyT

)iNuC-eF(91B-elbaTxidneppA

natnatsnoC-reppoC

TEPYT 8B-elbaTxidneppA

–UepyT

)iNuC-uC(81B-elbaTxidneppA

:etoNemasehthcihwrofesohT.dradnatstehtniderevoctonsinoitseuqnielpuocomrehtehttahtsetacidnielbatehtninwardenilA.1

.tnereffiderasemanriehtfinevesFMElamrehtdradnatsemasehtevahnevigsirebmuntnemucod.39-032EMTSA:..F.M.Elamrehtecnereferelpuocomrehtsetalugerhcihw.S.Uehtfodradnatslanoitanasi39'MTSA.2

11TI 6B0A1-01E

2.4 ToleranceTolerances with respect to temperature are shown in Table 11:

Table 10 Thermocouple Tolerances (JIS C 1602-1995)sepyT 1ssalcecnareloT 2ssalcecnareloT 3ssalcecnareloT

BepyTegnarerutarepmeT

eulavecnareloTegnarerutarepmeT

eulavecnareloT

----

--

0071otC˚006 °C± 5200.0 • |t|

006 ° 008otC °CC˚4+

008 ° 0071otC °C± 500.0 • |t|

SepyT,RepyTegnarerutarepmeT


eulavecnareloT

001otC˚0 °C±1°C

0011 ° 0061otC °C± 300.0+1[

])0011-t( °C

0° 006+otC °C± 5.1 °C

0061otC˚006 °C± 5200.0 • |t|

----

NepyT,KepyTegnarerutarepmeT


eulavecnareloT

04- ° 573otC °C± 5.1 °C

573 ° 0001otC °C± 400.0 • |t|

04- ° 333+otC °C± 5.2 °C

333 ° 0021otC °C± 5700.0 • |t|

761- ° 04+otC °C± C˚5.2

002- ° 761-otC °C± 510.0 • |t|

EepyTegnarerutarepmeT


eulavecnareloT

04- ° 573+otC °C± 5.1 °C

573 ° 008otC °C± 400.0 • |t|

04- ° 333+otC °C± 5.2 °C

333 ° 009otC °C± 5700.0 • |t|

761- ° 04+otC °C± 5.2 °C

002- ° 761-otC °C± 510.0 • |t|

JepyTegnarerutarepmeT


eulavecnareloT

04- ° 573+otC °C± 5.1 °C

573 ° 057otC °C± 400.0 • |t|

04- ° 333+otC °C± 5.2 °C

333 ° 057otC °C± 5700.0 • |t|

----

TepyTegnarerutarepmeT


eulavecnareloT

04- ° 521+otC °C± 5.0 °C

521 ° 053otC °C± 400.0 • |t|

04- ° 331+otC °C±1°C

331 ° 053otC °C± 5700.0 • |t|

76- ° 04+otC °C±1°C

002- ° 76-otC °C± 510.0 • |t|

:etoNnideificepssecnarelotgnirutcafunamehtteemotdeilppusyllameoneraslairetamelpuocomrehT.1

ehtnihtiwllaftonyam,revewoh,slairetamesehT.C˚04-evobaserutarepmetrofelbatehtfI.NdnaK,E,Tsepytrof3ssalcrednunevigserutarepmetwolrofsecnarelotgnirutcafunam

resahcrupeht2ro1ssalcfoesohtsallewsa,3ssalcfostimilteemrofderiuqereraselpuocomreht.deriuqeryllaususislairetamfonoitcelessa,sihtetatsllahs

2.5 Themocouple Electrical CharacteristicsElectrical characteristics is as shown in Table 12.

Insulation resistance is applied to routine unit test. Dielectric strength is applied to typetest.

Table 11 Electrical CharacteristicsmetI scitsiretcarahC

otdeilppaylnO(ecnatsisernoitalusnI)ebutnoitcetorphtiwselpuocomreht

slanimretneewtebecnatsisernoitalusnInahteromsiebutnoitcetorpdna

CDV005/WM01

otdeilppaylnO(htgnertscirtceleiD)ebutnoitcetorphtiwselpuocomreht

etunimenorofCAV005

TI 6B0A1-01E12

2.6 Thermocouple operating LimitsNormal operating limits are the temperatures that are generally recommended forcontinuous use in air. Overheat operating limits are the temperatures for short-perioduse not sharply defined limiting temperatures, but rather those at which operations forthe times indicated in Table 13 will not result in thermal EMF changes greater than thevalues also shown in that table for continuous operation in clean air.

Table 12 Thermocouple Continuous-Operation Times

edoC

)h(emitnoitarepo-suounitnoCynata)%(egnahcFMElamrehT

timilerutarepmetgnitarepolamrontAtimil

gnitarepotaehrevotA

BRSNKEJT

0002000200020000100001000010000100001

050505052052052052052

± 5.0± 5.0± 5.0± 57.0± 57.0± 57.0± 57.0± 57.0

13TI 6B0A1-01E

2.7 Thermocouple Leadwire ResistancesAlthough electronic instruments almost unaffected by thermocouple leadwire resistance,it can cause problems in the case of moving coil instruments and may require compensa-tion, so the user should follow any directions given in the manual for the instrument.

Table 14 shows thermocouple resistance R0 at 0˚C, and resistance R20 at 20˚C. Table15 shows the resistance ratios Rt/R20 and Rt/R0, between resistance values R20 and R0and resistance value Rt at t˚C. When compensating for this resistance with moving-coilinstruments, it is customary to treat half of the thermocouple’s specified length as beingat the operating temperature, and the other half as the room temperature.

Table 13 Thermocouple Resistances

Code for component materials B R S K E J T NOld code (reference)

- - - CA CRC IC CC -Wire diameter in mm

0.32 - - - - - - 6.17 -

0.50 1.75 1.47 1.43 - - - - -

0.65 - - - 2.95 3.56 1.70 1.50 3.94

1.00 - - - 1.25 1.50 0.72 0.63 1.66

1.60 - - - 0.49 0.59 0.28 0.25 0.65

2.30 - - - 0.24 0.28 0.14 - 0.31

3.20 - - - 0.12 0.15 0.07 - 0.16

Unit: Ω/m

Table 14 Thermocouple Resistance Ratios (Rt/R0 and Rt/R20)Code B R S K E J T N

Old code – – CA CRC IC CC –Temperature (t) ˚C Rt/R0 Rt/R20 Rt/R0 Rt/R20 Rt/R0 Rt/R20 Rt/R0 Rt/R20 Rt/R0 Rt/R20 Rt/R0 Rt/R20 Rt/R0 Rt/R20 Rt/R0

0 1.00 0.97 1.00 0.95 1.00 0.95 1.00 0.98 1.00 1.00 1.00 0.98 1.00 1.00 1.00

20 1.03 1.00 1.05 1.00 1.05 1.00 1.02 1.00 1.01 1.00 1.02 1.00 1.00 1.00 1.02

100 1.17 1.13 1.24 1.17 1.25 1.17 1.10 1.08 1.02 1.02 1.10 1.08 1.01 1.01 1.15

200 1.34 1.29 1.46 1.40 1.48 1.39 1.18 1.16 1.05 1.05 1.22 1.19 1.02 1.02

300 1.50 1.45 1.68 1.61 1.71 1.61 1.26 1.23 1.08 1.08 1.34 1.34 1.03 1.03

400 1.65 1.60 1.94 1.85 1.97 1.83 1.32 1.29 1.11 1.11 1.55 1.52

500 1.80 1.74 2.12 2.02 2.16 2.03 1.37 1.34 1.13 1.13 1.78 1.74600 1.95 1.88 2.32 2.22 2.37 2.23 1.41 1.38 1.16 1.15 2.04 2.00

700 2.10 2.03 2.52 2.41 2.58 2.43 1.45 1.42 1.18 1.18 2.35 2.30

800 2.25 2.17 2.72 2.60 2.75 2.61 1.50 1.47 1.20 1.20 2.69 2.44

900 2.39 2.31 2.90 2.78 2.97 2.80 1.54 1.51

1000 2.53 2.45 3.04 2.95 3.16 2.97 1.59 1.56

1100 2.66 2.57 3.26 3.12 3.34 3.14 1.64 1.61

1200 2.79 2.70 3.43 3.28 3.52 3.30 1.68 1.65

1300 2.92 2.82 3.59 3.44 3.68 3.46

1400 3.04 2.94 3.75 3.59 3.85 3.62

1500 3.16 3.06 3.90 3.73 4.00 3.77

1600 3.28 3.17

1700 3.40 3.29

TI 6B0A1-01E14

3. MINERAL INSULATED THERMOCOUPLES

3.1 ConstructionMineral Insulated thermocouples are filled with a powdered inorganic insulator (Mgo)between the metal sheath and the thermocouple element, and are of a single construc-tion. Table 16 shoes the dimensions of Mineral Insulated thermocouples.

Table 15 Mineral Insulated Thermocouple Dimensionsmm:tinU

htaehslateMDretemaidretuo

tnemeleelpuocomrehTdretemaid

tssenkcihthtaehslateM

0.1 ± 50.06.1 ± 50.02.3 ± 50.08.4 ± 50.04.6 ± 50.00.8 ± 50.0

latemfoeromro%51retemaidretuohtaehs

latemfoeromro%01retemaidretuohtaehs

Figure 2 Cross Section of Mineral Insulated Themocouple

(1) Longitudinal section of the measuring junction of an earthed thermocouple

(2) Longitudinal section of the measuring junction of an insulated thermocouple

Figure 3 Constructions of Measuring Junctions

15TI 6B0A1-01E

3.2 TolerancesTable 16 shows tolerances. These are determined in conformance with those forgeneral thermocouples.

Table 16 Tolerance classes for thermocouples (reference junction at 0˚C)

epyTecnareloT

1ssalcecnareloT

2ssalcecnareloT

3ssalc

TepyTegnarerutarepmeT


eulavecnareloT

04- ° 52+otC °C± 5.0 °C

521 ° 053otC °C± 400.0 • |t|

04- ° 331+otC °C±1°C

331 ° 053otC °C± 5700.0 • |t|

76- ° 04+otC °C±1°C

002 ° 76-otC °C± 510.0 • |t|

EepyTegnarerutarepmeT


eulavecnareloT

04- ° 573+otC °C± 5.1 °C

573 ° 008otC °C± 400.0 • |t|

04- ° 333+otC °C± 5.2 °C

333 ° 009otC °C± 5700.0 • |t|

761- ° 04+otC °C± 5.2 °C

002- ° 761-otC °C± 510.0 • |t|

JepyTegnarerutarepmeT


eulavecnareloT

04- ° 573+otC °C± 5.1 °C

573 ° 057otC °C± 400.0 • |t|

04- ° 333+otC °C± 5.2 °C

333 ° 057otC °C± 5700.0 • |t|

––––

NepyT,KepyTegnarerutarepmeT


eulavecnareloT

04- ° 573+otC °C± 5.1 °C

573 ° 0001otC °C± 400.0 • |t|

04- ° 333+otC °C± 5.2 °C

333 ° 0021otC °C± 5700.0 • |t|

761- ° 04+otC °C± 5.2 °C

002- ° 761-otC °C± 510.0 • |t|

:etoNtnemerusaemehtgnitcartbusybdetaluclacecnereffidehtroftimilmumixamehtsiecnarelotehT)1(

dradnatsehtgnisuFMElamrehtehtmorfdetrevnocerutarepmetehtmorferutarepmetnoitcnujforegralehtsiecnarelotehT.elbatFMElamreht ° %roC

nideificepssecnarelotgnirutcafunamehtteemotdeilppusyllameoneraslairetamelpuocomrehT)2(04-evobaserutarepmetrofelbateht ° ehtnihtiwllaftonyam,revewoh,slairetamesehT.C

fI.NdnaK,E,Tsepytrof3ssalcrednunevigserutarepmetwolrofsecnarelotgnirutcafunamresahcrupeht2ro1ssalcfoesohtsallewsa,3ssalcfostimilteemrofderiuqereraselpuocomreht

.deriuqeryllaususislairetamfonoitcelessa,sihtetatsllahs

TI 6B0A1-01E16

3.3 Codes and Normal Operating LimitsThe code for a Mineral Insulated thermocouple is the same as that for a regular thermo-couple with an S added at the beginning . Table 14 shows the normal operating limitsfor Mineral Insulated thermocouples. The codes for the materials used for the sheath areas follows:

A : Austenitic stainless steel (SUS 347, SU S316)B : Nickel-Chromium heat-resistant alloy (Inconel)

Table 17 Normal Operating Limits for Mineral Insulated Thermocouples (JIS C 1605-1995)

edoCretemaiDretuOhtaehS

mm

htaehSlateM °C

A B

NS 5.0 006

0.2,)6.1(,5.1,0.1 056

)2.3(,0.3 057

)8.4(,5.4 008 009

)8.4(,5.4 008 009

)4.6(,0.6 008 0001

0.8 009 0501

KS 5.0 006

0.2,)6.1(,5.1,0.1 056

)2.3(,0.3 057

)8.4(,5.4 008 009

)4.6(,0.6 008 0001

0.8 009 0501

ES 5.0 006

0.2,)6.1(,5.1,0.1 056

)2.3(,0.3 057

)8.4(,5.4 008 009

)4.6(,0.6 008 009

0.8 008 009

JS 5.0 004

0.2,)6.1(,5.1,0.1 054

)2.3(,0.3 056

)8.4(,5.4 057

)4.6(,0.6 057

0.8 057

TS 5.0 003

0.2,)6.1(,5.1,0.1 003

)2.3(,0.3 053

)8.4(,5.4 053

)4.6(,0.6 053

0.8 053

Notes:1. The normal operating limit is the temperature at which the device can be used continuously in air.2. The normal operating limits differ from those in JIS C 1602 due to the large dependence on the heat-

resistance of the metal sheath.3. ( ) will be removed in the future.

17TI 6B0A1-01E

3.4 Electrical Characteristics(Insulation Resistance, Thermocouple Leadwire Resistance)

Insulation resistances and thermocouple leadwire resistances are as shown in Table 19.

Table 20 shows sheathed thermocouple leadwire resistances. Due to the large variationsin sheathed thermocouple leadwire resistances, no standards are prescribed. Table 20presents some examples for reference:

Table 18 Electrical Characteristics

metIretuOhtaehSlateM

)mm(retemaiDscitsiretcarahC

ecnatsisernoitalusnI 0.2,)6.1(,5.1,0.1,5.0 M02> Ω CDV001/

,0.6,)8.4(,5.4,)2.3(,0.30.8,)4.6(

M001> Ω CDV005/

htgnertscirtceleiD )6.1(,5.1,0.1 etunimenorofCAV001

,0.6,)8.4(,5.4,)2.3(,0.30.8,)4.6(

etunimenorofCAV005

Notes:

(1) These tests should not be applied to earthed thermocouples.(2) For thermocouples with compensating cable, apply the smaller of the above values or insulation resis-

tances regulated in JIS C 1610.(3) ( ) will be removed in the future.

Table 19 Mineral insulated Thermocouple Leadwire Resistances

Sheath Outer diameter (mm)

SK SJ ST SE

Standard resistance

Maximum resistance

Standard resistance

Maximum resistance

Standard resistance

Maximum resistance

Standard resistance

Maximum resistance

219.49 – – – – – – –

1.0 40.32 55.22 23.81 32.44 – – – –

1.6 16.34 19.75 9.65 11.65 7.94 9.61 – –

3.2 3.15 3.74 1.87 2.2 1.61 1.90 3.77 4.46

4.8 1.40 1.50 0.84 0.93 0.70 0.78 1.70 1.80

6.4 0.79 0.89 0.48 0.54 0.40 0.45 0.94 1.10

8.0 0.66 0.73 0.38 0.44 0.32 0.37 0.77 0.87

2.2 16.31 19.8 – – – – – –

3.2 7.72 8.79 4.60 5.20 3.80 4.40 – –

4.8 3.43 4.08 2.10 2.50 1.70 2.10 – –

6.4 1.93 2.20 1.20 1.30 0.94 1.10 – –

8.0 1.24 1.44 0.75 0.82 1.63 0.69 1.48 1.73

Unit: Ω/m

Note: Resistance dispersion is ±20%

TI 6B0A1-01E18

4. EXTENTION AND COMPENSATING CABLETable 21 shows the types (codes), component materials, operating temperatures, toler-ances and colors for compensating cable. In the revision of JIS C1610 (Compensatingcable) of July 1995, types (codes), operating temperatures, tolerances, and colors werechanged. Especially for the color of the cable cover, Division 1 is newly added toconform to IEC standard. However, the former JIS color regulation still remains asDivision 2 so as not to cause accidents due to the color change when expanding orretrofitting existing systems. Use Division 2 as necessary.

Usage classification is shown in Table 22. Since operating temperature high limitextended to 200˚C, FEP (teflon) is newly added to insulator types. As usage classifica-tion is determined by insulator material, conditions are described in the notes of Table22.

Table 23 shows insulator resistance. Standard values differ according to the materials.

Table 20 Compensating Cable CharacteristicsfosepyT

CTdenibmoc

elbaCgnitasnepmoCsepyT

slairetaMtnenopmoCegnar.pmeT

)ecnarelotrof((° )C

ecnareloT(µ )V

edoCroloCecafruS

edoC edoC edoCdlO edis+ edis- 1ssalC 2ssalC 1.viD 2.viD

B CB XB reppoC reppoC 001ot0 – – yarG yarG

R ACR XR reppoC yliramirp,yollAdnareppoC

lekciN

001ot0 – 03 egnarO kcalB

BCR 001ot0 – 06

S ACS XS 001ot0 – 03 egnarO kcalB

BCS 002ot0 – 06

N XN – yliramirp,yollAdnalekciN

emorhC

yliramirp,yollAdnalekciN

nociliS

002ot52– 06 001 kniP –

CN – yliramirp,yollAdnareppoC

lekciN


lekciN

051ot0 – 001

K XK XK yliramirp,yollAdnalekciN

emorhC

yliramirp,yollAlekciN

002ot52– 06 001 neerG eulB

ACK – 051ot0 – 001

BCK XW nocI yliramirp,yollAdnareppoC

lekciN

051ot0 – 001

CCK XV reppoC yliramirp,yollAdnareppoC

lekciN

001ot0 – 001

E XE XE yliramirp,yollAdnalekciN

emorhC


lekciN

002ot52– 021 002 elpruP elpruP

J XJ XJ norI yliramirp,yollAdnareppoC

lekciN

002ot52– 58 041 kcalB wolleY

T XT XT reppoC yliramirp,yollAdnareppoC

lekciN

001ot52– 03 06 nworB nworB

gnitarepoelbacrofsadna,srotcudnocfoecnarelotehtnihtiwebdluohstniopnoitasnepmocnoitcnuj-ecnereferehttaerutarepmetehT:etoN.ytiroirprehgihanevigsinoitacifissalcegasu22elbat,egnarerutarepmet

19TI 6B0A1-01E

Table 21 Usage Classification:tinU °C

egasUnoitacifssalC

edoCdlO

edoCfoslairetaM

rotalusnIgnitarepO

erutarepmeTsetoN

esulareneG G G lyniV 09+ot02- BCSdnaBCRrofelbacilppatoN)1BCL,ACK,CN,ACS,ACR,CBfoegnarerutarepmetgnitarepO)2

0morfsiCCK ° C 09+ot ° C

egnarelddiM H H nrayssalG 051+ot0 .XTroCCK,ACS,ACR,CBrofelbacilppatoN

egnarhgiH S – PEF 002+ot52- .srotcudnocgnitasnepmocrofelbacilppatoN)152-morfsiXTfoegnarerutarepmetgnitarepO)2 ° 001+otC ° C

Table22 Insulator ResistanceM:tinU Ω mk•

egasUnoitacifssalC

sedoCfoslairetaM

rotalusnInoitalusnIecnatsiseR

esulareneG G lyniV 05

egnarelddiM H nrayssalG 50.0

egnarhgiH S PEF 0001

Table 23 Extension and Compensating Cable Resistance

elbacnoitnetxEecnatsiserlacirtcelE

tamm56.0,retemaideriwdael(02 ° ,C Ω )mk/

detsiwtfoecnatsiserlacirtcelE02tasrotcudnoc °C Ω mk/

seriw7 seriw4

)edis+XT,CCK,CS,CR/sedishtobCB(reppoC 92.55 09.7 42.41

)edis+XJ,BCK(norI 0.844 29.56 4.511

)edis-CS,CR(yollalekciN-reppoC 0.402 20.03 35.25

)edis–XK(lemulA 0.288 0.621 5.022

)edis+XK(lemorhC 1412 8.503 2.535

)edis-XJ(yollalekciN-reppoC 7951 5.332 2.114

)edis+XE(lemorhC 0.288 0.621 5.022

)edis-XE(yollalekciN-reppoC 7951 5.332 2.114

)edis-XT(yollalekciN-reppoC 7951 5.332 2.114

)edis-CCK(yollalekciN-reppoC 7951 5.332 2.114

TI 6B0A1-01E20

5. INTERNATIONAL TEMPERATURE SCALE

5.1 International Temperature Scale PlanAs with other physical quantities, because temperatures must be expressed the sameinternationally, they are expressed with a temperature scale based on a resolution passedat a general meeting of the International Weights and Measures Committee. The oldinternational temperature scale, the 1968 International Practical Temperatures Scale(IPTS-68), was revised by the 78th International Weights and Measures Commuitee inSeptember of 1989 based on a resolution from the 18th general meeting of the Interna-tional Weights and Measures Committee which met in 1987. The 1990 InternationalTemperature Scale (ITS-90) was adopted as the new international temperature scale, andhas been in effect internationally since January 1,1990.

These changes in the international temperature scale solved problems found in IPTS-68through advances in measurement technology centering on the latest thermodynamictemperature measurements. The international temperature scale plan is guided by thefollowing three principles:

(1) The plan specifies repeatable thermal equilibrium states, which are assigned tempera-tures to define fixed points.

(2) The plan assigns a standard thermometer for each temperature range, calibrated tothe defining fixed points.

(3) The plan establishes interpolation formulas that decide the relationships betweentemperatures (international temperatures) and standard thermometer indicatedtemperatures (output values) in order to interpolate between the defining fixed points.

Although the temperature concepts are based on thermodynamic temperatures, sinceabsolute measurement of thermodynamic temperatures is not possible, improvementsthat bring the international temperature scale closer to thermodynamic temperatures are amatter of repetition along with progress in measurement techniques. Gas and radiationthermometers are used as thermodynamically well-defined thermometers in the measure-ment of thermodynamic temperatures. However, although a gas thermometer in prin-ciple determines thermodynamic temperature from a comparison of pressure at idealstates using ideal gasses, in fact since no ideal gas actually exists and an ideal statecannot be perfectly attained, we can only arrange conditions close to the ideal and addcorrections to the best of our ability to determine the true values. Thus, in keeping withprogress in measurement techniques, corrections are incorporated into the temperaturesof the defining fixed points. Previously, a new international temperature scale had beenadopted roughly every twenty years. The ITS-90 now in use has been adopted as anattempt to faithfully arrive at the thermodynamic temperatures using state-of-the-arttechniques. However, because advanced techniques were required to achieve ITS-90,these endeavors are entrusted to the techniques of specialists at organizations studyingtemperature measurements.

21TI 6B0A1-01E

5.2 Essentials of the 1990 International Temperature Scale (ITS-90)ITS-90 is intended to solve certain problems found in the 1968 International PracticalTemperature Scale (IPTS-68). The main corrections are as follows:

(1) The low temperature range is expanded, and is defined to 0.65K.(2) The range previously defined by thermocouples (630.74 to 1064.43˚C) is replaced by

a range up to 961.78˚C defined using a platinum resistance thermometer, while therange above 961.78˚C is defined using a radiation thermometer.

(3) The defining fixed points have been changed, with the boiling points of oxygen,water, and neon being eliminated and replaced by several triple points and freezingpoints, and the temperatures at the defining fixed points overall have been changed.The relationship between the defining fixed points of the ITS-90 and the instrumentsfor interpolation is shown in Table 25. Because the temperatures for the definingfixed points have changed overall, the t90-t68 Temperature Difference shown inTable 26 has been changed based on these definition changes

Table 24 Comparison of IPTS-68 and ITS-90

Interpolation instrumentsInterpolation instruments T68/K T90/K t90/˚C

Helium vapor pressure scale

Gas thermometer

Platinum resistance thermometer

Plank's law of radiation

Platinum resistance thermometer

Plank's law of radiation

S thermocouple

-29.3467

-248.5939

-218.7916

-189.3442

-38.8344

0.01

29.7646

156.5985

231.928

419.527

660.323

961.78

1064.18

1084.62

13.81

17.042

20.28

27.102

54.361

83.798

90.188

273.16

373.15

505.1181

692.73

903.9

1235.58

1337.58

He (V)

e - H2 (T)

(B)e - H2 (V)

(B)e - H2 (V)

Ne (T)

Ne (B)

O2 (T)

Ar (T)

O2 (C)

Hg (T)

H2O (T)Ga (M)

H2O (V)

In (F)

Sn (F)

Zn (F)

Al (F)

Ag (F)

Au (f)

Cu (F)

0.65

3 to 5

13.8033

to 17

to 20.3

24.5561

54.3584

83.8058

234.3156

273.16

302.9146

429.7485

505.078

692.677

933.473

1234.93

1337.33

1357.77

Note: Descriptions of defining fixed-point states:B: Boiling point (state of equilibrium between the liquid phase and gas phase at one atmosphere of pressure)C: Condensation point (state of equilibrium between the liquid phase and gas phase at one atmosphere of pressure at which the

liquid phase condenses)F: Freezing point (state of equilibrium between the liquid phase and solid phase)M: Melting point (state of equilibrium between the solid phase liquid phase)T: Triple point (state of equilibrium between the solid phase, liquid phase, and gas phase)V: Vapor pressure point (state of equilibrium between the liquid phase and gas phase)

TI 6B0A1-01E22

5.3 Influence of ITS-90 on Industrial ThermometersBecause industrial thermometers conform to JIS, the temperature differences due todefinition changes, and their relationship to JIS, are matters of importance. Since thetemperature differences accompanying definition changes are small, on a practical leveltheir influence can be ignored (see Figure 4).

The areas where the effects of ITS-90 become a problem for the temperature related JISstandards are in the standard thermal EMF tables for thermocouples, and the standardresistance are in the standard thermal EMF tables for thermocouples, and the standardresistance tables for resistance thermometers sensors. Because the temperatures for thecurrent standard tables are regulated by IPTS-68, the switch to ITS-90 requres that thesebe changed by the temperature difference (t90 - t68). Because the JIS tolerances fortemperature sensors are specified with respect to the standard tables, the influence ofITS-90 becomes clear when the temperature differences due to definition changes arecompared to the tolerances.

The maximum temperature difference due to a definition change in the region up to1100˚C is + 0.36˚C at 780˚C. The value of this corresponds to 11% of the tolerance(3.1˚C) of a Class 0.4 thermocouple, and can, in practice, be ignored. Although for aClass 0.25 thermocouple the change at 780˚C reaches nearly half of the tolerance, thispresents no problems because Class 0.25 applies only to Types R and S thermocouples,and these are usually used at 1000˚C and above. The operating limits for RTSs are650˚C for Pt100, and 500˚C for JPt100. The largest change in the range up to 650˚C is0.115˚C at 600˚C; this value is 10% of the tolerance of + 1.35˚C for a Class A type, andcan be ignored in practice.

Although as explained above there is no problem in viewing the transition to ITS-90 ashaving no practical effect on industrial thermometry, there are instances in which theapplication of ITS-90 required for precision measurements such as temperature measure-ment in scientific research for determining physical constants. In such cases, tempera-ture measurements should be converted according to the values in Table 26.

accu

racy

˚C

Figure 4 Temperature Difference in International Temperature Scales, and JIS Toler-ances

23TI 6B0A1-01E

Table 25 Differences Between ITS-90 and IPTS-68

TI 6B0A1-01E24

APPENDIX TABLE A1-1 PT100 REFERENCE RESISTANCE TABLEThis table shows values specified by JIS C 1604-1989 and JIS C1606-1989.

Pt100 Resistance thermometer sensor (JIS C1604-1989) (JIS C1606-1989)

25TI 6B0A1-01E

APPENDIX TABLE A1-2 PT100 REFERENCE RESISTANCES

The reference resistances in Appendix Table A1 are calculated in the following equa-tions:

-200˚C to 0˚C range:Rt = R0 [1 + At + Bt2 + C (t - 100) t3]0˚C to + 650 ˚C range:Rt =R0 (1 + At + Bt2)Where: A = 3.90802 x 10-3˚C -01B = -5.802 x 10 - 7˚C - 2C = -4.2735 x 10 - 12˚C - 4

Notes: 1. R0 is 100Ω, and Rt represents the resistance at t˚C.2. The above expressions were used to calculate the reference resistances for this

standard, and are not intended to be used to determine the characteristics ofany individual RTS.

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APPENDIX TABLE A2-1 JPT100 REFERENCE RESISTANCE TABLEThis is the JPt100 reference resistance table defined in JISC1604 and JISC1606.

JPt 100RTS (JISC1604-1989) (JISC1606-1989)

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APPENDIX TABLE A2-2 JPT100 REFERENCE RESISTANCE TABLE

JPT100RTS continued from the previous page.

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APPENDIX TABLE A3-1 RT50 REFERENCE RESISTANCE TABLEAbolished after January 1, 1989.

Pt 50 Ω RTS.

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APPENDIX TABLE A3-2 PT50 REFERENCE RESISTANCE TABLEAbolished after January 1, 1989.

Pt 50 Ω (Continued from the previous page)

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APPENDIX TABLE A4-1 PT100 REFERENCE RESISTANCE TABLEThis is the reference resistance table defined in IEC Pub 751-1995. JIS C 1604-1997.

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APPENDIX TABLE A4-2 PT100 REFERENCE RESISTANCE TABLE

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APPENDIX TABLE A5 INTERPOLATION EQUATION FOR PT100 REFER-ENCE RESISTANCE

The reference resistances in Appendix A4 Pt100 reference resistance table (IEC 751-1995) are calculated in the following equations;

-200˚C to 0˚C range: Rt = Ro [1 + At + Bt2 + C(t - 100)t3]0˚C to 850˚C range: Rt = Ro (1 + At + Bt2)Where; A = 3.9083 x 10-3˚C-1

B = -5.775 x 10-7˚C-2

C = -4.183 x 10-12˚C-4

Notes: 1. Ro is 100Ω, and Rt represents the resistance at t˚C.2. The above expressions were used to calculate the reference resistances for this

standard, and are not intended to be used to determine the characteristics ofany individual RTS.

APPENDIX TABLE A6 INTERPOLATION EQUATION FOR JPT100 REFER-ENCE RESISTANCE

The reference resistances in Appendix A2 JPt100 reference resistance table (JIS C1604-1989) are calculated in the following equations:

For 0°C to 630°C range,Rt = Ro (1 + At1 + Bt12) (1)Where; A = 0.3974973 x 10-2

B = -0.58973 x 10-6

t' is obtained in equation (2)

t' = t - 0.045 ( ) ( - 1) ( - 1) ( - 1) (2)

For -200°C to 0°C range,

Rt = Ro ∑ ai ti (3)

Where; a0 = 0 a1 = 3.971686 x 10-3

a2 = -1.157433 x 10-6

a3 = -2.051844 x 10-8

a4 = -3.629438 x 10-10

a5 = -3.157615 x 10-12

a6 = -1.369914 x 10-14

a7 = -2.303654 x 10-17

Notes: 1. R0 is 100Ω, and Rt represents the resistance at t°C. 2. The tolerance of calculation error in the equation (2) is less than 0.000019°C. 3. The tolerance of calculation error in the equation (3) is less than 0.0035°C.

t'100

t'100

t'419.58

t'630.74

i = 7

i = 0

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APPENDIX TABLE B1-1 TYPE B THERMOCOUPLE THERMAL E.M.F.TABLE

This is the reference thermal e.m.f. table defined in JIS C1602-1995.

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C 1602-1995


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C 1602-1995


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C 1602-1995


Remarks: The temperature at the reference-junction compensation point is set at 0˚C

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C 1602-1995

APPENDIX TABLE B2-1 TYPE R THERMOCOUPLE THERMAL E.M.F.TABLE

This is the reference thermal e.m.f. table defined in JIS C1602-1995

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C 1602-1995


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C 1602-1995


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C 1602-1995


Remarks: The temperature at reference-junction compensation point is set at 0˚C.

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C 1602-1995

APPENDIX TABLE B3-1 TYPE S THERMOCOUPLE THERMAL E.M.F.TABLE


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C 1602-1995


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C 1602-1995


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C 1602-1995


Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

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C 1602-1995

APPENDIX TABLE B4-1 TYPE N THERMOCOUPLE THERMAL E.M.F.TABLE


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C 1602-1995


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C 1602-1995



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C 1602-1995

APPENDIX TABLE B5-1 TYPE K THERMOCOUPLE THERMAL E.M.F.TABLE


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C 1602-1995


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C 1602-1995


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C 1602-1995



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C 1602-1995

APPENDIX TABLE B6-1 TYPE E THERMOCOUPLE THERMAL E.M.F.TABLE


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C 1602-1995


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C 1602-1995



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C 1602-1995

APPENDIX TABLE B7-1 TYPE J THERMOCOUPLE THERMAL E.M.F.TABLE


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C 1602-1995


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C 1602-1995



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C 1602-1995

APPENDIX TABLE B8-1 TYPE T THERMOCOUPLE THERMAL E.M.F.TABLE


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C 1602-1995



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C 1602-1995

APPENDIX TABLE B9 INTERPOLATION EQUATION OF REFERENCETHERMAL E.M.F. of JIS'95 (JIS C1602-1995)

These equations are applied to Appendix Tables B1 to B8.E: Reference thermal e.m.f.t: Temperature (˚C)

Remarks: This table is applied to calculate Appendix table B1 type B thermocouple thermal e.m.f..

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C 1602-1995

Remarks: This table is applied to calculate Appendix table B2 type R thermocouple thermal e.m.f..

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C 1602-1995

Remarks: This table is applied to calculate Appendix table B3 type S thermocouple thermal e.m.f..

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C 1602-1995

Remarks: This table is applied to calculate Appendix table B4 type N thermocouple thermal e.m.f..

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C 1602-1995

Remarks: This table is applied to calculate Appendix table B5 type K thermocouple thermal e.m.f..

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C 1602-1995

Remarks: This table is applied to calculate Appendix table B6 type E thermocouple thermal e.m.f..

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C 1602-1995

Remarks: This table is applied to calculate Appendix table B7 type J thermocouple thermal e.m.f..

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C 1602-1995

Remarks: This table is applied to calculate Appendix table B8 type T thermocouple thermal e.m.f..

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This is the reference thermal e.m.f. table defined in JISC1602-1981.

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This is the reference thermal e.m.f. table defined in JISC1602-1981 (Type K) JISC1605-1982 (Type SK).

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This is the reference thermal e.m.f. table defined in JISC1602-1981 (Type E) andJISC1605-1982 (Type SE).

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This is the reference thermal e.m.f. table defined in JISC1602-1981 (Type J) andJISC1605-1982 (Type SJ).

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This is the reference thermal e.m.f. table defined in JISC1602-1981 (Type T) andJISC1605-1982 (Type ST).

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APPENDIX TABLE B17. INTERPOLATION EQUATION OF REFERENCETHERMAL E.M.F. of JIS'81 (JIS C1602-1981, abol-ished after July 1995)

These equations are applied to Appendix Table B10 to 16.E: Reference thermal e.m.ft: Temperature (˚C)

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APPENDIX TABLE B18-1 Cu-CuNi THERMOCOUPLE THERMAL E.M.F.TABLE (DIN 43710 TYPE U)

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APPENDIX TABLE B18-2 Cu-CuNi THERMOCOUPLE THERMAL E.M.F.TABLE (DIN 43710 TYPE U)

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APPENDIX TABLE B19-1 Fe-CuNi THERMOCOUPLE THERMAL E.M.F.TABLE (DIN 43710 TYPE L)

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APPENDIX TABLE B20-1 W (W5Re/W26Re) THERMOCOUPLE REFERENCETHERMAL E.M.F. TABLE (ASTM E988)

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APPENDIX TABLE B21 KP/Au•Fe THERMOCOUPLE REFERENCE THER-MAL E.M.F. TABLE

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APPENDIX TABLE B22 TABLE OF THERMOCOUPLE REFERENCE THER-MAL E.M.F. PRACTICED IN TABLES OTHERTHAN THOSE DEFINED IN JIS.

Subject to change without notice.Printed in Japan, 703/b(YG)

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