International Thermocouple Colour Codes — Thermocouple and Extension Grade Wires

ANSI Code

Alloy Combination

Colour 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

‡IRON
Fe
(magnetic)

CONSTANTAN
COPPER- NICKEL
Cu-Ni

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%

CHROMEGA NICKEL- CHROMIUM
Ni-Cr

ALOMEGA NICKEL- ALUMINIUM
Ni-Al
(magnetic)

-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%

COPPER
Cu

CONSTANTAN COPPER- NICKEL
Cu-Ni

NONE ESTABLISHED

0 to 80°C
(32 to 176°F)
Ext. Grade

COPPER
Cu

CONSTANTAN COPPER- NICKEL
Cu-Ni

-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%

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							Reducing, Vacuum, Inert. Limited Use in Oxidising at High Temperatures Not Recommended for Low Temperatures
K							Clean Oxidising and Inert. Limited Use in Vacuum or Reducing. Wide Temperature Range. Most Popular Calibration
V*							Alternative to KX Type Extension Wire for Low Temperatures; Not Recommended for General Use
T							Mild Oxidising, Reducing Vacuum or Inert. Good Where Moisture is Present, Low Temperature and Cryogenic Applications

International Thermocouple Colour Codes — Thermocouple and Extension Grade Wires

ANSI Code

Alloy Combination

Colour 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

CHROMEGA NICKEL- CHROMIUM
Ni-Cr

CONSTANTAN COPPER- NICKEL
Cu-Ni

-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%

OMEGA-P NICROSIL
Ni-Cr-Si

OMEGA-N NISIL
Ni-Si-Mg

-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%

PLATINUM
13% RHODIUM
Pt-13% Rh

PLATINUM
PT

NONE ESTABLISHED

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%

PLATINUM
10% RHODIUM
Pt-10% Rh

PLATINUM
PT

NONE ESTABLISHED

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%

ANSI CODE	NETHERLANDS GERMAN to DIN 43710	Comments Environment - Bare Wire

E		Oxidising or Inert. Limited Use in Vacuum or Reducing. Highest EMF Change per Degree
N	No Standard Use American Colour Codes	Alternative To Type K More Stable at High Temps
R		Oxidising or Inert. Do Not Insert in Metal Tubes. Beware of Contamination. High Temperature
S		Oxidising or Inert. Do Not Insert in Metal Tubes. Beware of Contamination. High Temperature

International Thermocouple Colour Codes — Thermocouple and Extension Grade Wires

ANSI Code

Alloy Combination

Colour 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

COPPER
Cu

COPPER-LOW NICKEL
Cu-Ni

NONE ESTABLISHED

0 to 50°C
(32 to 122°F)
Ext. Grade

PLATINUM
30% RHODIUM
Pt-30% Rh

PLATINUM
6% RHODIUM
Pt-6% Rh

NONE ESTABLISHED

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

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

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

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

ANSI CODE	CZECH BRITISH to BS 1843	NETHERLANDS GERMAN to DIN 43710	FRENCH to NFC 42-324	Comments Environment - Bare Wire

U*				Extension Grade Connecting Wire for R & S Thermocouples; Also Known as RX and SX Extension Wire
B	No Standard Use Copper Wire		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 Colour Codes		Vacuum, Inert, Hydrogen. Beware of Embrittlement. Not Practical Below 399°C (750°F). Not for Oxidising Atmosphere
C* (W5)		No Standard Use American Colour Codes		Vacuum, Inert, Hydrogen. Beware of Embrittlement. Not Practical Below 399°C (750°F). Not for Oxidising Atmosphere
D* (W3)		No Standard Use American Colour Codes		Vacuum, Inert, Hydrogen. Beware of Embrittlement. Not Practical Below 399°C (750°F). Not for Oxidising Atmosphere