International Thermocouple Color Codes — Thermocouple and Extension Grade Wires

US flag Canadian flag
ANSI Code Alloy Combination Thermocouple Color Coding Maximum Temperature Useful Range EMF (mV) Over Max. Temperature Range Limits of Error**
(Whichever is Greater)
+Lead -Lead Thermocouple Grade Extension Grade
Standard Special
J ‡IRON
Fe
(magnetic)
CONSTANTAN
COPPER- NICKEL
Cu-Ni
W R B Plug W R K Plug 0 to 750°C
(32 to 1382°F)
Therm. Grade
0 to 200°C
(32 to 392°F)
Ext. Grade
-8.095 to 69.553 0 to 750°C (32 to 1382°F)
 

 

2.2°C or 0.75%  1.1°C or 0.4% 

K CHROMEGA NICKEL- CHROMIUM
Ni-Cr
ALOMEGA NICKEL- ALUMINIUM
Ni-Al
(magnetic)
Y R B Plug Y R Y Plug -200 to 1250°C
(-328 to 2282°F)
Therm. Grade
0 to 200°C
(32 to 392°F)
Ext. Grade
-6.458 to 54.886 -200 to 1250°C (-328 to 2282°F)  
2.2°C or 0.75%
Above 0°C
2.2°C or 2.0%
Below 0°C
1.1°C or 0.4%
V* COPPER
Cu
CONSTANTAN COPPER- NICKEL
Cu-Ni
NONE ESTABLISHED NONE ESTABLISHED 0 to 80°C
(32 to 176°F)
Ext. Grade
     
T COPPER
Cu
CONSTANTAN COPPER- NICKEL
Cu-Ni
Bl R B Plug Bl R B Plug -200 to 350°C
(-328 to 662°F)
Therm. Grade
-60 to 100°C
(-76 to 212°F)
Ext. Grade
-6.528 to 20.872 -200 to 350°C (-328 to 662°F)
1.0°C or 0.75%
Above 0°C
1.0°C or 1.5%
Below 0°C
0.5°C or 0.4%

  Czech flag UK flag Dutch flag German flag Japan flag French flag  
ANSI
CODE
International
IEC 584-3
International
IEC 584-3
Intrinsically Safe
CZECH
BRITISH
to
BS 1843
NETHERLANDS
GERMAN
to DIN 43710
JAPANESE
to
JIS C
1610-1981
FRENCH
to
NFC 42-324
Comments
Environment -
Bare Wire
J K W K Plug K W Bl Plug Y Bl K Plug R Bl Bl Plug R W Y Plug Y K K Plug Reducing, Vacuum, Inert. Limited Use in Oxidising at High Temperatures Not Recommended for Low Temperatures
K G W G Plug G W Bl Plug B Bl R Plug R G G Plug R W Bl Plug Y P Y Plug Clean Oxidising and Inert. Limited Use in Vacuum or Reducing. Wide Temperature Range. Most Popular Calibration
V* G W G Plug G W Bl Plug W Bl R Plug   R W Bl Plug Y B R Plug Alternative to KX Type Extension Wire for Low Temperatures; Not Recommended for General Use
T B W B Plug B W Bl Plug W Bl Bl Plug R B B Plug R W B Plug Y Bl Bl Plug Mild Oxidising, Reducing Vacuum or Inert. Good Where Moisture is Present, Low Temperature and Cryogenic Applications

International Thermocouple Color Codes — Thermocouple and Extension Grade Wires

  US flag Canadian flag
ANSI Code Alloy Combination Thermocouple Color Coding Maximum Temperature Useful Range EMF (mV) Over Max. Temperature Range Limits of Error**
(Whichever is Greater)
+Lead -Lead Thermocouple Grade Extension Grade Standard Special
E CHROMEGA NICKEL- CHROMIUM
Ni-Cr
CONSTANTAN COPPER- NICKEL
Cu-Ni
P R B Plug P R P Plug -200 to 900°C
(-328 to 1652°F)
Therm. Grade
0 to 200°C
(32 to 392°F)
Ext. Grade
-9.835 to 76.373 -200 to 900°C (-328 to 1652°F)
1.7°C or 0.5%
Above 0°C
1.7°C or 1.0%
Below 0°C
1.0°C or 0.4%
N OMEGA-P NICROSIL
Ni-Cr-Si
OMEGA-N NISIL
Ni-Si-Mg
O R B Plug O R O Plug -270 to 1300°C
(-450 to 2372°F)
Therm. Grade
0 to 200°C
(32 to 392°F)
Ext. Grade
-4.345 to 47.513 2.2°C or 0.75%
Above 0°C
2.2°C or 2.0%
Below 0°C
1.1°C or 0.4%
R PLATINUM
13% RHODIUM
Pt-13% Rh
PLATINUM
PT
NONE ESTABLISHED K R G Plug 0 to 1450°C
(32 to 2642°F)
Therm. Grade
0 to 150°C
(32 to 300°F)
Ext. Grade
-0.226 to 21.101 0 to 1450°C (32 to 2642°F)
 

 

1.5°C or 0.25% 0.6°C or 0.1%

S PLATINUM
10% RHODIUM
Pt-10% Rh
PLATINUM
PT
NONE ESTABLISHED K R G Plug 0 to 1450°C
(32 to 2642°F)
Therm. Grade
0 to 150°C
(32 to 300°F)
Ext. Grade
-0.236 to 18.693 0 to 1450°C (32 to 2642°F)
 

 

1.5°C or 0.25% 0.6°C or 0.1%


    Czech flag UK flag Dutch flag German flag Japan flag French flag  
ANSI
CODE
International
IEC 584-3
International
IEC 584-3
Intrinsically Safe
CZECH
BRITISH
to
BS 1843
NETHERLANDS
GERMAN
to DIN 43710
JAPANESE
to
JIS C
1610-1981
FRENCH
to
NFC 42-324
Comments
Environment -
Bare Wire
E P W P Plug P W Bl Plug B Bl B Plug R K K Plug R W P Plug Y P P Plug Oxidising or Inert. Limited Use in Vacuum or Reducing. Highest EMF Change per Degree
N Pk W Pk Plug Pk W Bl Plug O Bl O Plug No Standard
Use American Color Codes
Alternative To Type K
More Stable at High Temps
R O W O Plug O W Bl Plug W Bl G Plug R W W Plug R W K Plug Y G G Plug Oxidising or Inert. Do Not Insert in Metal Tubes. Beware of Contamination. High Temperature
S O W O Plug O W Bl Plug W Bl G Plug R W W Plug R W K Plug Y G G Plug Oxidising or Inert. Do Not Insert in Metal Tubes. Beware of Contamination. High Temperature

International Thermocouple Color Codes — Thermocouple and Extension Grade Wires

  US flag Canadian flag
ANSI Code Alloy Combination Thermocouple Color Coding Maximum Temperature Useful Range EMF (mV) Over Max. Temperature Range Limits of Error**
(Whichever is Greater)
+Lead -Lead Thermocouple Grade Extension Grade Standard Special
U* COPPER
Cu
COPPER-LOW NICKEL
Cu-Ni
NONE ESTABLISHED K R G Plug 0 to 50°C
(32 to 122°F)
Ext. Grade
     
B PLATINUM
30% RHODIUM
Pt-30% Rh
PLATINUM
6% RHODIUM
Pt-6% Rh
NONE ESTABLISHED Gy R Gy Plug 0 to 1700°C
(32 to 3092°F)
Therm. Grade
0 to 100°C
(32 to 212°F)
Ext. Grade
0 to 13.820 0 to 1700°C (32 to 3092°F)
 

 

0.5% over
800°C
Not
Established

G*
(W) 
TUNGSTEN
W
TUNGSTEN- 26% RHENIUM
W-26% Re
NONE ESTABLISHED W R W Bl Plug 0 to 2320°C
(32 to 4208°F)
Therm. Grade
0 to 260°C
(32 to 500°F)
Ext. Grade
0 to 38.564 4.5°C to 425°C
1.0% to 2320°C
Not
Established
C*
(W5) 
TUNGSTEN- 5% RHENIUM
W-5% Re
TUNGSTEN- 26% RHENIUM
W-26% Re
NONE ESTABLISHED W R W R Plug 0 to 2320°C
(32 to 4208°F)
Therm. Grade
0 to 870°C
(32 to 1600°F)
Ext. Grade
0 to 37.066 4.5°C to 425°C
1.0% to 2320°C
Not
Established
D*
(W3) 
TUNGSTEN- 3% RHENIUM
W-3% Re
TUNGSTEN- 25% RHENIUM
W-25% Re
NONE ESTABLISHED W R W Y Plug 0 to 2320°C
(32 to 4208°F)
Therm. Grade
0 to 260°C
(32 to 500°F)
Ext. Grade
0 to 39.506 4.5°C to 425°C
1.0% to 2320°C
Not
Established
*Not Official Symbol or Standard   ‡Extension Grade   **ASTM Standard E230-87, 1992 Annual Book of ASTM Standards
      Czech flag UK flag Dutch flag German flag Japan flag French flag  
ANSI
CODE
International
IEC 584-3
International
IEC 584-3
Intrinsically Safe
CZECH
BRITISH
to
BS 1843
NETHERLANDS
GERMAN
to DIN 43710
JAPANESE
to
JIS C
1610-1981
FRENCH
to
NFC 42-324
Comments
Environment -
Bare Wire
U* O W O Plug O W Bl Plug W Bl G Plug R W W Plug R W K Plug Y G G Plug Extension Grade Connecting Wire for R & S Thermocouples; Also Known as RX and SX Extension Wire
B     No Standard
Use Copper Wire
R Gy Gy Plug R Gy Gy Plug No Standard
Use Copper Wire
Oxidising or Inert. Do Not Insert in Metal Tubes. Beware of Contamination. High Temperature. Common Use in Glass Industry
G*
(W) 
      No Standard
Use American Color Codes
Vacuum, Inert, Hydrogen. Beware of Embrittlement. Not Practical Below 399°C (750°F). Not for Oxidising Atmosphere
C*
(W5) 
      No Standard
Use American Color Codes
Vacuum, Inert, Hydrogen. Beware of Embrittlement. Not Practical Below 399°C (750°F). Not for Oxidising Atmosphere
D*
(W3) 
      No Standard
Use American Color Codes
Vacuum, Inert, Hydrogen. Beware of Embrittlement. Not Practical Below 399°C (750°F). Not for Oxidising Atmosphere