This document provides technical information on resistance thermometer sensors (RTSs) and thermocouples, emphasizing their importance in industrial temperature measurement. It includes updates on international standards, operational parameters, and the revisions made to conform with the 1990 international temperature scale. The document aims to assist users in understanding the standards and applications for accurate temperature measurement.

1. Technical
Information
Yokogawa Electric Corporation
Resistance Thermometer Sensor and
Thermocouple Data Collection
TI 6B0A1-01E
© Copyright Oct. 1990 (YK)
3rd Edition: May 2003 (YG)
Introduction
Resistance thermometer sensors (RTSs) and thermocouples are the temperature sensors most widely used in industrial
temperature measurement. They have the advantages of simple construction and ease of use, making for convenience in
measurement.
However, if correct application methods based on the proper standards are not followed, highly accurate measurements
cannot be expected.
This document is a compendium of the basic data relating to resistance thermometer sensors and thermocouples. *This
second edition reflects IEC and JIS revisions (thermocouples) of July 1995. We hope that this document will aid you in
comparing 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 .................................................................................................. 1
1.1 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 ............................................................................................................................................ 6
2.1 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 ............................................................................................. 14
3.1 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 .............................................................................................. 20
5.1 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

2. TI 6B0A1-01E
APPENDIX A RESISTANCE THERMOMETER SENSORS
APPENDIX 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 THERMOCOUPLES
APPENDIX 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

3. 1TI 6B0A1-01E
1. Resistance Thermometer Sensors
Resistance thermometer sensors (RTSs) are temperature sensors that make use of the
physical property where electrical resistance in metal increases proportionally with an
increase in temperature. Since platinum RTSs can be expected to provide the most
accurate temperature measurement of all industrial temperature sensors, they are widely
used, especially in conditions near room temperature.
One of the requirements for an industrial thermometer sensor is that its performance and
characteristics be guaranteed by a standard. Platinum RTSs have been standardized
under JIS C 1604 ("Resistance Thermometer Sensors") and JIS C 1606 ("Sheathed
Resistance Thermometer Sensors") in Japan, and standardized under IEC-751 ("Indus-
trial Platinum Resistance Thermometer Sensors") abroad. These standards were recently
revised one after another. This document explains the revisions and summarizes the
essential data based on the new standards.
1.1 Overview of the IEC Revisions
IEC-751 was revised in July, 1995. The major change in this revision is to revise
reference resistance in accordance with the temperatures of the 1990 International
Temperature Scale (ITS-90). ITS-90 has adopted as the new International Temperature
Scale since January 1, 1990 (Refer to 5. International Temperature Scale of this
document). IEC had started study to revise IEC-751 reference resistance immediately
after ITS-90 adoption, and finally accomplished.
1.2 Overview of the JIS Revisions
Resistance thermometer sensors JIS was revised in February, 1997. This revision made
JIS 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 (Resistance
thermometer sensors) and JIS C 1606 (Sheathed resistance thermometer sensors) is
abolished.
(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 1990
International Temperature Scale (ITS-90) which is adopted in IEC standard. As for
the new resistance reference resistance table, refer to Table A5 Resistance table at
the end of this document.
Figure 1 shows the difference between reference resistance values of JIS'89 Pt100
and 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. This
difference is bigger than the temperature difference between the old International
Temperature Scale (IPTS-68) and ITS-90 (Refer to 5.3 Influence of ITS-90 on
Industrial Thermometers). Comparing the temperature differences to the tolerances
at measured value 500˚C, it is about one fifth of the tolerance in class A, and less
than one tenth in class B, so their influence can be ignored on a practical industrial
use level. However, in using digital device which resolution is 0.1˚C or less than
that, 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 the
new JIS. With regard to JPt100, it was already announced that it would be abolished
in the future at the last time revision (January, 1989). However, considering the

4. TI 6B0A1-01E2
situation that they have been used for more than thirty years and many of them are
still in use, the 1989 reference resistance table remains in the guide. It is also
described in the guide that the characteristics of JPt100 are almost the same as those
of Pt100 so that the quality of supplement is guaranteed. This Technical Information
provides reference resistance tables of abolished JPt100, JIS'89 Pt100 and JIS'91
50Ω(Pt50) for reference.
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700
t/˚C
∆t/˚C

5. 3TI 6B0A1-01E
1.3 Types of Resistance Thermometer Sensors
The types of RTSs specified in JIS C 1604 and JIS C 1606 are standardized, as shown
in Table 2, according to the standard resistance element R100/R0 value, Class, rated
current, operating temperature range, and lead wire system.
Table 1 Resistance Thermometer Sensors (JIS C 1604-1989, JIS C 1606-1989)
edoC eulav0R/001R ssalC tnerrucdetaR
erutarepmetgnitarepO
egnar
metsyseriwdaeL
001tP 0583.1
AssalC
BssalC
Am1
Am2
*Am5
L
M
H
C˚001ot002-
C˚053ot0
C˚056ot0
*eriw-2
eriw-3
eriw-4
)001PJ( )6193.1(
AssalC
BssalC
Am1
Am2
*Am5
L
M
H
C˚001ot002-
C˚053ot0
C˚056ot0
*eriw-2
eriw-3
eriw-4
:etoN
001taeulavecnatsiserehtsi001R.1 ° .C
001foeulavecnatsiserehtsi0R.2 Ω fota ° .C
.deunitnocsidsisesehtnerapnimetinA.3
.AssalCniylppatonod*nahtiwdekramsmetI.4
005+ot0siHegnarerutarepmetgnitareposSTRdehtaehS.5 ° .C
.sSTRdehtaehsotelbacilppatonsimetsyseriwdaeleriw-2ehT.6
1.4 Tolerances vs. Temperature
Tolerances with respect to temperature must be within the ranges in Table 3 throughout
the operating temperature ranges. Table 4 shows samples of tolerance versus measured
temperature. If the measured temperature t °C in Table 3 includes a fractional value
below the decimal point, the tolerance range includes the smaller value. To avoid the
risk of disputes in judgment as a result of exceeding measurement capability, the
following guidelines are used for rounding off the tolerances: In Class A the number of
valid significant digits below the decimal point is two, rounded down from three. In
Class B the number of valid significant digits below the decimal point is one, rounded
down 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 temperature
subtracted from the temperature computed from the resistance value displayed by the resistance
element 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.

6. TI 6B0A1-01E4
Table 3
:stinU °C
erutarepmetderusaeM
ecnareloT
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 to
Appendix 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
:etoN
desivereblliw4061CSIJ,egnahcsihtotmrofnocoT.5991,yluJnidesiversawelbatecnatsiserdradnatS157CEI
.noos
1.5 Temperature/Resistance relationships Values in Various Nations
Table 5 shows a comparison of resistance thermometer characteristics. IEC standards
were standardized in Pub 751 in 1983. Due to intensifying international influence, JIS
was revised to accept these in January of 1989. Note that there are significant differ-
ences between JPt100 and Pt100.

7. 5TI 6B0A1-01E
1.6 Copper Resistance Thermometer Sensors
There are no standards for copper RTSs in JIS, and they have been little used in general
industry, but they are found in rotating electrical equipment, primarily to measure
temperatures of coils, bearings, etc. The following shows the nominal resistances and
the standard resistance element Rt/Ro standardized in JEM 1252 (Japan Electrical
Manufacturers’ Association) for RTSs in rotating electrical equipment.
Table 5 Nominal Resistance
foepyT
ecnatsiser
tnemele
lanimoN
ecnatsiser
dradnatS
erutarepmet
DTRreppoC
01 Ω 52 °C
52 Ω 0°C
Table 6 Standard Resistance Element Rt/Ro Copper Resistance Thermometer Sensors
erutarepmeT °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

8. TI 6B0A1-01E6
2. THERMOCOUPLES
Thermocouples sense temperatures based on the principle that an electrical current is
generated when two different metals are combined in a closed circuit and subjected to a
temperature 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 which
have demonstrated their reliability, have become the objects of standardization. This
document deals primarily with those thermocouples standardized in the JIS, plus other
typically used thermocouples that have been field-proven in particular applications.
2.1 Overview of the JIS '95 Revisions
JIS standards related to thermocouples were revised as of July 1, 1995. The major
purpose of this revision is to make these JIS standards conform to the international
standard IEC 584. Thermocouple codes, thermal EMF, and tolerance classes were
revised to match IEC584, so JIS standard data are consistent with the standards used
abroad now.
The major changes are "N thermocouple is newly stipulated" and "standard thermal
EMFs revised". As shown in Figure 1, the difference between JIS'89 and JIS'95 thermal
EMFs will have little effect on industrial temperature measurement.
Figure 1 Revised Value of Thermal EMF

9. 7TI 6B0A1-01E
2.2 Types of Thermocouples
In most cases, a thermocouple’s type is indicated by a code. Since the codes specified
in 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 8
shows 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.

10. TI 6B0A1-01E8
Table 7 Thermocouple Codes, Component Materials, Normal Operating Limits, and
Overheat Operating Limits (JIS C 1602-1981)
edoC
dlO
edoc
slairetamtnenopmoC
ssalC
tnemelE
retemaid
)mm(
lamroN
gnitarepo
(stimil ° )C
taehrevO
gnitarepo
(stimil ° )C
seitreporP
edis+ edis–
B –
%03sniatnoC
.muidohR
-munitalP
yollamuidohR
%6sniatnoC
.muidohR
-munitalP
yollamuidohR
2ssalC
3ssalC
05.0 0051 0071
yrevsiFMElamrehT
moortallams
.erutarepmet
nisecnereffidegraL
scitsiretcarahc
.neessemitemos
saemasehtesiwrehtO
.RepyT
R –
%31sniatnoC
.muidohR
.munitalP
yollamuidohR
munitalP
2ssalC
05.0 0041 0061
saelbatiuS.elbatsyreV
.elpuocomrehtdradnats
evisorrocrofelbatiuS
.stnemnorivne
,negordyhotevitisneS
llamS.sropavlatem
yreV.FMElamreht
.egnahcralucesthgils
eriwnoisnetxeegraL
.rorre
S –
%01sniatnoC
.muidohR
.munitalP
yollamuidohR
munitalP 05.0 0041 0061
N
yliramirp,yollA
,emorhC,lekciN
nociliSdna
yliramirp,yollA
dna,lekciN
nociliS
1ssalC
2ssalC
3ssalC
56.0 058 009 noisorroctnellecxE
semitlareves(ecnatsiser
oN.)KepyTfotaht
oteudnoitarenegrorre
.gniredroegnar-trohs
dleifcitengaM
ylevitalerecneulfni
.llams
00.1 059 0001
06.1 0501 0011
03.2 0011 0511
02.3 0021 0521
K AC
yliramirp,yollA
dnalekciN
emorhC
yliramirp,yollA
lekciN
1ssalC
2ssalC
3ssalC
56.0 056 058
.ytiraenilFMEdooG
enisorrocrofelbatiuS
tnatsiseR.tnemnorivne
.sropavlatemot
.egnahcralucesemoS
00.1 057 059
06.1 058 0501
03.2 009 0011
02.3 0001 0021
E CRC
yliramirp,yollA
dnalekciN
emorhC
yliramirp,yollA
dnareppoC
lekciN
1ssalC
2ssalC
3ssalC
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 norI
yliramirp,yollA
dnareppoC
lekciN
1ssalC
2ssalC
3ssalC
56.0 004 005 ylriafhtiw,tsocwoL
.FMElamrehtegral
.ytiraenilFMEdooG
gnicuderrofelbatiuS
egraL.stnemnorivne
elpmas-ot-elpmas
nisnoitairav
.ytilauq,scitsiretcarahd
tastfirD.ylisaestsuR
.serutarepmethgih
00.1 054 055
06.1 005 056
03.2 055 057
02.3 006 057
T CC reppoC
yliramirp,yollA
dnareppoC
lekciN
1ssalC
2ssalC
3ssalC
23.0 002 052 dooghtiw,tsocwoL
erutarepmet-wol
dooG.scitsiretcarahc
rofelbatiuS,ytiraenil
.stnemnorivnegnicuder
eriwnoisnetxeegraL
.rorre
56.0 002 052
00.1 052 003
06.1 003 053

11. 9TI 6B0A1-01E
Table 8 Non-JIS Thermocouples in practical Use
emaN
slairetamtnenopmoC gnitarepO
erutarepmet
taehrevOegnar
)(nitimil
seitreporP
FMElamrehtdradnatS
ytirohtuadna,elbat
edis+ edis-
-munitalP
muidohR
%02sniatnoC
.muidohR
-ohR-munitalP
yollamuid
%5sniatnoC
.muidohR
-ohR-munitalP
yollamuid
0051ot003 °C
0081( ° )C
.serutarepmethgihtaelbasU
.FMElamrehtllamS
.RepyTsaemas,esiwrehtO
22BelbaTxidneppA
%04sniatnoC
.muidohR
-ohR-munitalP
yollamuid
%02sniatnoC
.muidohR
-ohR-munitalP
yollamuid
0061ot0011 °C
0081( ° )C
-netsgnuT
muinehR
%5sniatnoC
.muidohR
-ohR-munitalP
yollamuid
%62sniatnoC
.muidohR
-ohR-munitalP
yollamuid
0042ot0 °C
0003( ° )C
gnicuderrofelbatiuS
,sessagtreni,stnemnorivne
.eligarF.sagnegordyh
02BselbaTxidneppA
48-889EMTSA
%3sniatnoC
.muidohR
-ohR-munitalP
yollamuid
%52sniatnoC
.muidohR
-ohR-munitalP
yollamuid 22BelbaTxidneppA
48-889EMTSA
netsgnuT
%62sniatnoC
.muidohR
-ohR-munitalP
yollamuid
lenitalP
,yollA
yliramirp
,muidallaP
dna,muitalP
dloG
,yollA
dloGyliramirp
muidallaPdna
0011ot0 °C
0031( ° )C
.noisarbaotecnatsiserhgiH
ehtylraenFMElamrehT
.KepyTfotahtsaemas
SBN22BelbaTxidneppA
.lov,hcraeseRfolanruoJ
80N.C86
/lemorhC
norI-dloG
,yollA
yliramirp
dnalekciN
0?4oemorhC
)lemorhC(
70.0sniatnoC
.norI%elom
yollanorI-dloG
K003ot1
ylevitalerFMElamrehT
.wolebdnaK02taegral
.ytiraenilFMEdooG
034TPSMTSA
12BelbaTxidneppA

12. TI 6B0A1-01E10
2.3 Thermal EMF Characteristics
The standard thermal EMFs of the various thermocouple types are shown in Appendix
Tables B1 through B19.
Because JIS C 1602-1995 was written to be consistent with the standards used in other
countries, 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 EMF
document selections for the individual national and international standards. Equations
for interpolation of standard thermal EMFs are provided for reference at the end of this
document.
Table 9 Thermal EMF Document Selection List
cirenegelpuocomrehT
eman
noitangixeddradnatselpuocomrehT
FMElamrehtdradnatS
rebmuntnemucod
skrameRepytdradnatS
SIJ CEI ISNA SB NID
03-6/muidohR-munitalP BEPYT 1B-elbaTxidceppA
munitalP/muidohR-munitalP
REPYT 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
:etoN
emasehthcihwrofesohT.dradnatstehtniderevoctonsinoitseuqnielpuocomrehtehttahtsetacidnielbatehtninwardenilA.1
.tnereffiderasemanriehtfinevesFMElamrehtdradnatsemasehtevahnevigsirebmuntnemucod
.39-032EMTSA:..F.M.Elamrehtecnereferelpuocomrehtsetalugerhcihw.S.Uehtfodradnatslanoitanasi39'MTSA.2

13. 11TI 6B0A1-01E
2.4 Tolerance
Tolerances with respect to temperature are shown in Table 11:
Table 10 Thermocouple Tolerances (JIS C 1602-1995)
sepyT 1ssalcecnareloT 2ssalcecnareloT 3ssalcecnareloT
BepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
eulavecnareloT
-
-
-
-
-
-
0071otC˚006 °C
± 5200.0 • |t|
006 ° 008otC °C
C˚4+
008 ° 0071otC °C
± 500.0 • |t|
SepyT,RepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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,KepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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|
EepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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|
JepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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|
-
-
-
-
TepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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|
:etoN
nideificepssecnarelotgnirutcafunamehtteemotdeilppusyllameoneraslairetamelpuocomrehT.1
ehtnihtiwllaftonyam,revewoh,slairetamesehT.C˚04-evobaserutarepmetrofelbateht
fI.NdnaK,E,Tsepytrof3ssalcrednunevigserutarepmetwolrofsecnarelotgnirutcafunam
resahcrupeht2ro1ssalcfoesohtsallewsa,3ssalcfostimilteemrofderiuqereraselpuocomreht
.deriuqeryllaususislairetamfonoitcelessa,sihtetatsllahs
2.5 Themocouple Electrical Characteristics
Electrical characteristics is as shown in Table 12.
Insulation resistance is applied to routine unit test. Dielectric strength is applied to type
test.
Table 11 Electrical Characteristics
metI scitsiretcarahC
otdeilppaylnO(ecnatsisernoitalusnI
)ebutnoitcetorphtiwselpuocomreht
slanimretneewtebecnatsisernoitalusnI
nahteromsiebutnoitcetorpdna
CDV005/WM01
otdeilppaylnO(htgnertscirtceleiD
)ebutnoitcetorphtiwselpuocomreht
etunimenorofCAV005

14. TI 6B0A1-01E12
2.6 Thermocouple operating Limits
Normal operating limits are the temperatures that are generally recommended for
continuous use in air. Overheat operating limits are the temperatures for short-period
use not sharply defined limiting temperatures, but rather those at which operations for
the times indicated in Table 13 will not result in thermal EMF changes greater than the
values also shown in that table for continuous operation in clean air.
Table 12 Thermocouple Continuous-Operation Times
edoC
)h(emitnoitarepo-suounitnoC
ynata)%(egnahcFMElamrehT
timilerutarepmetgnitarepolamrontA
timil
gnitarepotaehrevotA
B
R
S
N
K
E
J
T
0002
0002
0002
00001
00001
00001
00001
00001
05
05
05
052
052
052
052
052
± 5.0
± 5.0
± 5.0
± 57.0
± 57.0
± 57.0
± 57.0
± 57.0

15. 13TI 6B0A1-01E
2.7 Thermocouple Leadwire Resistances
Although 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. Table
15 shows the resistance ratios Rt/R20 and Rt/R0, between resistance values R20 and R0
and resistance value Rt at t˚C. When compensating for this resistance with moving-coil
instruments, it is customary to treat half of the thermocouple’s specified length as being
at 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 N
Old 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 1.74
600 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

16. TI 6B0A1-01E14
3. MINERAL INSULATED THERMOCOUPLES
3.1 Construction
Mineral 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 Dimensions
mm:tinU
htaehslateM
Dretemaidretuo
tnemeleelpuocomrehT
dretemaid
tssenkcihthtaehslateM
0.1 ± 50.0
6.1 ± 50.0
2.3 ± 50.0
8.4 ± 50.0
4.6 ± 50.0
0.8 ± 50.0
latemfoeromro%51
retemaidretuohtaehs
latemfoeromro%01
retemaidretuohtaehs
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

17. 15TI 6B0A1-01E
3.2 Tolerances
Table 16 shows tolerances. These are determined in conformance with those for
general thermocouples.
Table 16 Tolerance classes for thermocouples (reference junction at 0˚C)
epyT
ecnareloT
1ssalc
ecnareloT
2ssalc
ecnareloT
3ssalc
TepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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|
EepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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|
JepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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,KepyT
egnarerutarepmeT
eulavecnareloT
egnarerutarepmeT
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|
:etoN
tnemerusaemehtgnitcartbusybdetaluclacecnereffidehtroftimilmumixamehtsiecnarelotehT)1(
dradnatsehtgnisuFMElamrehtehtmorfdetrevnocerutarepmetehtmorferutarepmetnoitcnuj
foregralehtsiecnarelotehT.elbatFMElamreht ° %roC
nideificepssecnarelotgnirutcafunamehtteemotdeilppusyllameoneraslairetamelpuocomrehT)2(
04-evobaserutarepmetrofelbateht ° ehtnihtiwllaftonyam,revewoh,slairetamesehT.C
fI.NdnaK,E,Tsepytrof3ssalcrednunevigserutarepmetwolrofsecnarelotgnirutcafunam
resahcrupeht2ro1ssalcfoesohtsallewsa,3ssalcfostimilteemrofderiuqereraselpuocomreht
.deriuqeryllaususislairetamfonoitcelessa,sihtetatsllahs

18. TI 6B0A1-01E16
3.3 Codes and Normal Operating Limits
The 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 limits
for Mineral Insulated thermocouples. The codes for the materials used for the sheath are
as 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)
edoC
retemaiDretuOhtaehS
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.

19. 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 variations
in sheathed thermocouple leadwire resistances, no standards are prescribed. Table 20
presents some examples for reference:
Table 18 Electrical Characteristics
metI
retuOhtaehSlateM
)mm(retemaiD
scitsiretcarahC
ecnatsisernoitalusnI 0.2,)6.1(,5.1,0.1,5.0 M02> Ω CDV001/
,0.6,)8.4(,5.4,)2.3(,0.3
0.8,)4.6(
M001> Ω CDV005/
htgnertscirtceleiD )6.1(,5.1,0.1 etunimenorofCAV001
,0.6,)8.4(,5.4,)2.3(,0.3
0.8,)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%

20. TI 6B0A1-01E18
4. EXTENTION AND COMPENSATING CABLE
Table 21 shows the types (codes), component materials, operating temperatures, toler-
ances and colors for compensating cable. In the revision of JIS C1610 (Compensating
cable) of July 1995, types (codes), operating temperatures, tolerances, and colors were
changed. Especially for the color of the cable cover, Division 1 is newly added to
conform to IEC standard. However, the former JIS color regulation still remains as
Division 2 so as not to cause accidents due to the color change when expanding or
retrofitting existing systems. Use Division 2 as necessary.
Usage classification is shown in Table 22. Since operating temperature high limit
extended 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 Table
22.
Table 23 shows insulator resistance. Standard values differ according to the materials.
Table 20 Compensating Cable Characteristics
fosepyT
CT
denibmoc
elbaCgnitasnepmoC
sepyT
slairetaMtnenopmoC
egnar.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,yollA
dnareppoC
lekciN
001ot0 – Ϯ 03 egnarO kcalB
BCR 001ot0 – Ϯ 06
S ACS XS 001ot0 – Ϯ 03 egnarO kcalB
BCS 002ot0 – Ϯ 06
N XN – yliramirp,yollA
dnalekciN
emorhC
yliramirp,yollA
dnalekciN
nociliS
002ot52– Ϯ 06 Ϯ 001 kniP –
CN – yliramirp,yollA
dnareppoC
lekciN
yliramirp,yollA
dnareppoC
lekciN
051ot0 – Ϯ 001
K XK XK yliramirp,yollA
dnalekciN
emorhC
yliramirp,yollA
lekciN
002ot52– Ϯ 06 Ϯ 001 neerG eulB
ACK – 051ot0 – Ϯ 001
BCK XW nocI yliramirp,yollA
dnareppoC
lekciN
051ot0 – Ϯ 001
CCK XV reppoC yliramirp,yollA
dnareppoC
lekciN
001ot0 – Ϯ 001
E XE XE yliramirp,yollA
dnalekciN
emorhC
yliramirp,yollA
dnareppoC
lekciN
002ot52– Ϯ 021 Ϯ 002 elpruP elpruP
J XJ XJ norI yliramirp,yollA
dnareppoC
lekciN
002ot52– Ϯ 58 Ϯ 041 kcalB wolleY
T XT XT reppoC yliramirp,yollA
dnareppoC
lekciN
001ot52– Ϯ 03 Ϯ 06 nworB nworB
gnitarepoelbacrofsadna,srotcudnocfoecnarelotehtnihtiwebdluohstniopnoitasnepmocnoitcnuj-ecnereferehttaerutarepmetehT:etoN
.ytiroirprehgihanevigsinoitacifissalcegasu22elbat,egnarerutarepmet

21. 19TI 6B0A1-01E
Table 21 Usage Classification
:tinU °C
egasU
noitacifssalC
edoC
dlO
edoC
foslairetaM
rotalusnI
gnitarepO
erutarepmeT
setoN
esulareneG G G lyniV 09+ot02- BCSdnaBCRrofelbacilppatoN)1
BCL,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)1
52-morfsiXTfoegnarerutarepmetgnitarepO)2 ° 001+otC ° C
Table22 Insulator Resistance
M:tinU Ω mk•
egasU
noitacifssalC
sedoC
foslairetaM
rotalusnI
noitalusnI
ecnatsiseR
esulareneG G lyniV 05
egnarelddiM H nrayssalG 50.0
egnarhgiH S PEF 0001
Table 23 Extension and Compensating Cable Resistance
elbacnoitnetxE
ecnatsiserlacirtcelE
tamm56.0,retemaideriwdael(
02 ° ,C Ω )mk/
detsiwtfoecnatsiserlacirtcelE
02tasrotcudnoc °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

22. TI 6B0A1-01E20
5. INTERNATIONAL TEMPERATURE SCALE
5.1 International Temperature Scale Plan
As with other physical quantities, because temperatures must be expressed the same
internationally, they are expressed with a temperature scale based on a resolution passed
at a general meeting of the International Weights and Measures Committee. The old
international temperature scale, the 1968 International Practical Temperatures Scale
(IPTS-68), was revised by the 78th International Weights and Measures Commuitee in
September 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 International
Temperature Scale (ITS-90) was adopted as the new international temperature scale, and
has been in effect internationally since January 1,1990.
These changes in the international temperature scale solved problems found in IPTS-68
through advances in measurement technology centering on the latest thermodynamic
temperature measurements. The international temperature scale plan is guided by the
following 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 to
the defining fixed points.
(3) The plan establishes interpolation formulas that decide the relationships between
temperatures (international temperatures) and standard thermometer indicated
temperatures (output values) in order to interpolate between the defining fixed points.
Although the temperature concepts are based on thermodynamic temperatures, since
absolute measurement of thermodynamic temperatures is not possible, improvements
that bring the international temperature scale closer to thermodynamic temperatures are a
matter of repetition along with progress in measurement techniques. Gas and radiation
thermometers 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 ideal
states using ideal gasses, in fact since no ideal gas actually exists and an ideal state
cannot be perfectly attained, we can only arrange conditions close to the ideal and add
corrections to the best of our ability to determine the true values. Thus, in keeping with
progress in measurement techniques, corrections are incorporated into the temperatures
of the defining fixed points. Previously, a new international temperature scale had been
adopted roughly every twenty years. The ITS-90 now in use has been adopted as an
attempt to faithfully arrive at the thermodynamic temperatures using state-of-the-art
techniques. However, because advanced techniques were required to achieve ITS-90,
these endeavors are entrusted to the techniques of specialists at organizations studying
temperature measurements.

23. 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 Practical
Temperature 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 the
range 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 freezing
points, 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 instruments
for interpolation is shown in Table 25. Because the temperatures for the defining
fixed points have changed overall, the t90-t68 Temperature Difference shown in
Table 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)

24. TI 6B0A1-01E22
5.3 Influence of ITS-90 on Industrial Thermometers
Because industrial thermometers conform to JIS, the temperature differences due to
definition changes, and their relationship to JIS, are matters of importance. Since the
temperature differences accompanying definition changes are small, on a practical level
their influence can be ignored (see Figure 4).
The areas where the effects of ITS-90 become a problem for the temperature related JIS
standards are in the standard thermal EMF tables for thermocouples, and the standard
resistance are in the standard thermal EMF tables for thermocouples, and the standard
resistance tables for resistance thermometers sensors. Because the temperatures for the
current standard tables are regulated by IPTS-68, the switch to ITS-90 requres that these
be changed by the temperature difference (t90 - t68). Because the JIS tolerances for
temperature sensors are specified with respect to the standard tables, the influence of
ITS-90 becomes clear when the temperature differences due to definition changes are
compared to the tolerances.
The maximum temperature difference due to a definition change in the region up to
1100˚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 a
Class 0.25 thermocouple the change at 780˚C reaches nearly half of the tolerance, this
presents 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 are
650˚C for Pt100, and 500˚C for JPt100. The largest change in the range up to 650˚C is
0.115˚C at 600˚C; this value is 10% of the tolerance of + 1.35˚C for a Class A type, and
can be ignored in practice.
Although as explained above there is no problem in viewing the transition to ITS-90 as
having no practical effect on industrial thermometry, there are instances in which the
application 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.
accuracy˚C
Figure 4 Temperature Difference in International Temperature Scales, and JIS Toler-
ances

25. 23TI 6B0A1-01E
Table 25 Differences Between ITS-90 and IPTS-68

26. TI 6B0A1-01E24
APPENDIX TABLE A1-1 PT100 REFERENCE RESISTANCE TABLE
This table shows values specified by JIS C 1604-1989 and JIS C1606-1989.
■ Pt100 Resistance thermometer sensor (JIS C1604-1989) (JIS C1606-1989)

27. 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 -01
B = -5.802 x 10 - 7˚C - 2
C = -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 of
any individual RTS.

28. TI 6B0A1-01E26
APPENDIX TABLE A2-1 JPT100 REFERENCE RESISTANCE TABLE
This is the JPt100 reference resistance table defined in JISC1604 and JISC1606.
■ JPt 100RTS (JISC1604-1989) (JISC1606-1989)

29. 27TI 6B0A1-01E
APPENDIX TABLE A2-2 JPT100 REFERENCE RESISTANCE TABLE
■ JPT100RTS continued from the previous page.

30. TI 6B0A1-01E28
APPENDIX TABLE A3-1 RT50 REFERENCE RESISTANCE TABLE
Abolished after January 1, 1989.
■ Pt 50 Ω RTS.

31. 29TI 6B0A1-01E
APPENDIX TABLE A3-2 PT50 REFERENCE RESISTANCE TABLE
Abolished after January 1, 1989.
■ Pt 50 Ω (Continued from the previous page)

32. TI 6B0A1-01E30
APPENDIX TABLE A4-1 PT100 REFERENCE RESISTANCE TABLE
This is the reference resistance table defined in IEC Pub 751-1995. JIS C 1604-1997.

33. 31TI 6B0A1-01E
APPENDIX TABLE A4-2 PT100 REFERENCE RESISTANCE TABLE

34. TI 6B0A1-01E32
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 of
any individual RTS.
APPENDIX TABLE A6 INTERPOLATION EQUATION FOR JPT100 REFER-
ENCE RESISTANCE
The reference resistances in Appendix A2 JPt100 reference resistance table (JIS C
1604-1989) 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

35. 33TI 6B0A1-01E
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.

36. TI 6B0A1-01E34
C 1602-1995
APPENDIX TABLE B1-2 TYPE B THERMOCOUPLE THERMAL E.M.F.
TABLE

37. 35TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B1-3 TYPE B THERMOCOUPLE THERMAL E.M.F.
TABLE

38. TI 6B0A1-01E36
C 1602-1995
APPENDIX TABLE B1-4 TYPE B THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C

39. 37TI 6B0A1-01E
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

40. TI 6B0A1-01E38
C 1602-1995
APPENDIX TABLE B2-2 TYPE R THERMOCOUPLE THERMAL E.M.F.
TABLE

41. 39TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B2-3 TYPE R THERMOCOUPLE THERMAL E.M.F.
TABLE

42. TI 6B0A1-01E40
C 1602-1995
APPENDIX TABLE B2-4 TYPE R THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at reference-junction compensation point is set at 0˚C.

43. 41TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B3-1 TYPE S THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JIS C1602-1995.

44. TI 6B0A1-01E42
C 1602-1995
APPENDIX TABLE B3-2 TYPE S THERMOCOUPLE THERMAL E.M.F.
TABLE

45. 43TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B3-3 TYPE S THERMOCOUPLE THERMAL E.M.F.
TABLE

46. TI 6B0A1-01E44
C 1602-1995
APPENDIX TABLE B3-4 TYPE S THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

47. 45TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B4-1 TYPE N THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JIS C1602-1995.

48. TI 6B0A1-01E46
C 1602-1995
APPENDIX TABLE B4-2 TYPE N THERMOCOUPLE THERMAL E.M.F.
TABLE

49. 47TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B4-3 TYPE N THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

50. TI 6B0A1-01E48
C 1602-1995
APPENDIX TABLE B5-1 TYPE K THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JIS C1602-1995.

51. 49TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B5-2 TYPE K THERMOCOUPLE THERMAL E.M.F.
TABLE

52. TI 6B0A1-01E50
C 1602-1995
APPENDIX TABLE B5-3 TYPE K THERMOCOUPLE THERMAL E.M.F.
TABLE

53. 51TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B5-4 TYPE K THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

54. TI 6B0A1-01E52
C 1602-1995
APPENDIX TABLE B6-1 TYPE E THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JIS C1602-1995.

55. 53TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B6-2 TYPE E THERMOCOUPLE THERMAL E.M.F.
TABLE

56. TI 6B0A1-01E54
C 1602-1995
APPENDIX TABLE B6-3 TYPE E THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

57. 55TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B7-1 TYPE J THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JIS C1602-1995.

58. TI 6B0A1-01E56
C 1602-1995
APPENDIX TABLE B7-2 TYPE J THERMOCOUPLE THERMAL E.M.F.
TABLE

59. 57TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B7-3 TYPE J THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

60. TI 6B0A1-01E58
C 1602-1995
APPENDIX TABLE B8-1 TYPE T THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JIS C1602-1995.

61. 59TI 6B0A1-01E
C 1602-1995
APPENDIX TABLE B8-2 TYPE T THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

62. TI 6B0A1-01E60
C 1602-1995
APPENDIX TABLE B9 INTERPOLATION EQUATION OF REFERENCE
THERMAL 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..

63. 61TI 6B0A1-01E
C 1602-1995
Remarks: This table is applied to calculate Appendix table B2 type R thermocouple thermal e.m.f..

64. TI 6B0A1-01E62
C 1602-1995
Remarks: This table is applied to calculate Appendix table B3 type S thermocouple thermal e.m.f..

65. 63TI 6B0A1-01E
C 1602-1995
Remarks: This table is applied to calculate Appendix table B4 type N thermocouple thermal e.m.f..

66. TI 6B0A1-01E64
C 1602-1995
Remarks: This table is applied to calculate Appendix table B5 type K thermocouple thermal e.m.f..

67. 65TI 6B0A1-01E
C 1602-1995
Remarks: This table is applied to calculate Appendix table B6 type E thermocouple thermal e.m.f..

68. TI 6B0A1-01E66
C 1602-1995
Remarks: This table is applied to calculate Appendix table B7 type J thermocouple thermal e.m.f..

69. 67TI 6B0A1-01E
C 1602-1995
Remarks: This table is applied to calculate Appendix table B8 type T thermocouple thermal e.m.f..

70. TI 6B0A1-01E68
APPENDIX TABLE B10-1 TYPE B THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JISC1602-1981.

71. 69TI 6B0A1-01E
APPENDIX TABLE B10-2 TYPE B THERMOCOUPLE THERMAL E.M.F.
TABLE

72. TI 6B0A1-01E70
APPENDIX TABLE B10-3 TYPE B THERMOCOUPLE THERMAL E.M.F.
TABLE

73. 71TI 6B0A1-01E
APPENDIX TABLE B10-4 TYPE B THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

74. TI 6B0A1-01E72
APPENDIX TABLE B11-1 TYPE R THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JISC1602-1981.

75. 73TI 6B0A1-01E
APPENDIX TABLE B11-2 TYPE R THERMOCOUPLE THERMAL E.M.F.
TABLE

76. TI 6B0A1-01E74
APPENDIX TABLE B11-3 TYPE R THERMOCOUPLE THERMAL E.M.F.
TABLE

77. 75TI 6B0A1-01E
APPENDIX TABLE B11-4 TYPE R THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

78. TI 6B0A1-01E76
APPENDIX TABLE B12-1 TYPE S THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JISC1602-1981.

79. 77TI 6B0A1-01E
APPENDIX TABLE B12-2 TYPE S THERMOCOUPLE THERMAL E.M.F.
TABLE

80. TI 6B0A1-01E78
APPENDIX TABLE B12-3 TYPE S THERMOCOUPLE THERMAL E.M.F.
TABLE

81. 79TI 6B0A1-01E
APPENDIX TABLE B12-4 TYPE S THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

82. TI 6B0A1-01E80
APPENDIX TABLE B13-1 TYPE K THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JISC1602-1981 (Type K) JISC1605-
1982 (Type SK).

83. 81TI 6B0A1-01E
APPENDIX TABLE B13-2 TYPE K THERMOCOUPLE THERMAL E.M.F.
TABLE

84. TI 6B0A1-01E82
APPENDIX TABLE B13-3 TYPE K THERMOCOUPLE THERMAL E.M.F.
TABLE

85. 83TI 6B0A1-01E
APPENDIX TABLE B13-4 TYPE K THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

86. TI 6B0A1-01E84
APPENDIX TABLE B14-1 TYPE E THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JISC1602-1981 (Type E) and
JISC1605-1982 (Type SE).

87. 85TI 6B0A1-01E
APPENDIX TABLE B14-2 TYPE E THERMOCOUPLE THERMAL E.M.F.
TABLE

88. TI 6B0A1-01E86
APPENDIX TABLE B14-3 TYPE E THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

89. 87TI 6B0A1-01E
APPENDIX TABLE B15-1 TYPE J THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JISC1602-1981 (Type J) and
JISC1605-1982 (Type SJ).

90. TI 6B0A1-01E88
APPENDIX TABLE B15-2 TYPE J THERMOCOUPLE THERMAL E.M.F.
TABLE

91. 89TI 6B0A1-01E
APPENDIX TABLE B15-3 TYPE J THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

92. TI 6B0A1-01E90
APPENDIX TABLE B16-1 TYPE T THERMOCOUPLE THERMAL E.M.F.
TABLE
This is the reference thermal e.m.f. table defined in JISC1602-1981 (Type T) and
JISC1605-1982 (Type ST).

93. 91TI 6B0A1-01E
APPENDIX TABLE B16-2 TYPE T THERMOCOUPLE THERMAL E.M.F.
TABLE
Remarks: The temperature at the reference-junction compensation point is set at 0˚C.

94. TI 6B0A1-01E92
APPENDIX TABLE B17. INTERPOLATION EQUATION OF REFERENCE
THERMAL 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.f
t: Temperature (˚C)

95. 93TI 6B0A1-01E

96. TI 6B0A1-01E94

97. 95TI 6B0A1-01E

98. TI 6B0A1-01E96
APPENDIX TABLE B18-1 Cu-CuNi THERMOCOUPLE THERMAL E.M.F.
TABLE (DIN 43710 TYPE U)

99. 97TI 6B0A1-01E
APPENDIX TABLE B18-2 Cu-CuNi THERMOCOUPLE THERMAL E.M.F.
TABLE (DIN 43710 TYPE U)

100. TI 6B0A1-01E98
APPENDIX TABLE B19-1 Fe-CuNi THERMOCOUPLE THERMAL E.M.F.
TABLE (DIN 43710 TYPE L)

101. 99TI 6B0A1-01E
APPENDIX TABLE B19-2 Fe-CuNi THERMOCOUPLE THERMAL E.M.F.
TABLE (DIN 43710 TYPE L)

102. TI 6B0A1-01E100
APPENDIX TABLE B19-3 Fe-CuNi THERMOCOUPLE THERMAL E.M.F.
TABLE (DIN 43710 TYPE L)

103. 101TI 6B0A1-01E
APPENDIX TABLE B20-1 W (W5Re/W26Re) THERMOCOUPLE REFERENCE
THERMAL E.M.F. TABLE (ASTM E988)

104. TI 6B0A1-01E102
APPENDIX TABLE B20-2 W (W5Re/W26Re) THERMOCOUPLE REFERENCE
THERMAL E.M.F. TABLE (ASTM E988)

105. 103TI 6B0A1-01E
APPENDIX TABLE B20-3 W (W5Re/W26Re) THERMOCOUPLE REFERENCE
THERMAL E.M.F. TABLE (ASTM E988)

106. TI 6B0A1-01E104
APPENDIX TABLE B20-4 W (W5Re/W26Re) THERMOCOUPLE REFERENCE
THERMAL E.M.F. TABLE (ASTM E988)

107. 105TI 6B0A1-01E
APPENDIX TABLE B21 KP/Au•Fe THERMOCOUPLE REFERENCE THER-
MAL E.M.F. TABLE

108. TI 6B0A1-01E106
APPENDIX TABLE B22 TABLE OF THERMOCOUPLE REFERENCE THER-
MAL E.M.F. PRACTICED IN TABLES OTHER
THAN THOSE DEFINED IN JIS.
Subject to change without notice.
Printed in Japan, 703/b(YG)