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Wire Color Codes and Limits of Error

View the printable version (Printable version also contains international color codes)
ANSI
Code		 Alloy Combination
Color Coding    
Maximum Useful
Temperature
Range ++		 Maximum
Thermocouple Grade
Temperature
Range		 EMF (mV)
Over Max.
Temperature
Range		 Standard Limits
of Error**
(above O°C)		 Special
Limits of Error**
(above O°C)		 International
IEC 584-3		 Comments
Environment —
Bare Wire		 IEC
Code
+ Lead - Lead Thermocouple
Grade		 Extension
Grade
J IRON
Fe
(magnetic)		 CONSTANTAN
COPPER-NICKEL
Cu-Ni		 Thermocouple Color Codes Thermocouple Grade:
32 to 1382°F
0 to 750°C
Extension Grade:
32 to 392°F
0 to 200°C		 –346 to 2193°F
–210 to 1200°C		 –8.095 to
69.553		 greater of
2.2°C or 0.75%		 greater of
1.1°C or 0.4%		 Reducing, Vacuum, Inert.
Limited Use in Oxidizing
at High Temperatures.
Not Recommended for
Low Temperatures.		 J
K CHROMEGA®
NICKELCHROMIUM
Ni-Cr		 ALOMEGA®
NICKEL-ALUMINUM
Ni-AI
(magnetic)		 Thermocouple Grade:
–328 to 2282°F
–200 to 1250°C
Extension Grade:
32 to 392°F
0 to 200°C		 –454 to 2501°F
–270 to 1372°C		 –6.458 to
54.886		 greater of
2.2°C or 0.75%		 greater of
1.1°C or 0.4%		 Clean Oxidizing and Inert.
Limited Use in Vacuum or
Reducing. Wide Temperature
Range, Most Popular Calibration		 K
T COPPER
Cu		 CONSTANTAN
COPPER-NICKEL
Cu–Ni		 Thermocouple Grade:
–328 to 662°F
–250 to 350°C
Extension Grade:
–76 to 212°F
–60 to 100°C		 –454 to 752°F
–270 to 400°C		 –6.258 to
20.872		 greater of
1.0°C or 0.75%		 greater of
0.5°C or 0.4%		 Mild Oxidizing,
Reducing Vacuum or Inert. Good
Where Moisture Is
Present. Low Temperature and
Cryogenic Applications		 T
E CHROMEGA®
NICKELCHROMIUM
Ni-Cr		 CONSTANTAN
COPPER-NICKEL
Cu-Ni		 Thermocouple Grade:
–328 to 1652°F
–200 to 900°C
Extension Grade:
32 to 392°F
0 to 200°C		 –454 to 1832°F
–270 to 1000°C		 –9.835 to
76.373		 greater of
1.7°C or 0.5%		 greater of
1.0°C or 0.4%		 Oxidizing or Inert.
Limited Use in Vacuum
or Reducing.
Highest EMF Change
Per Degree		 E
N OMEGA-P®
NICROSIL
Ni-Cr-Si		 OMEGA-N®
NISIL
Ni-Si-Mg		 Thermocouple Grade:
–450 to 2372°F
–270 to 1300°C
Extension Grade:
32 to 392°F
0 to 200°C		 –450 to 2372°F
–270 to 1300°C		 –4.345
to 47.513		 greater of
2.2°C or 0.75%		 greater of
1.1°C or 0.4%		 Alternative to Type K.
More Stable
at High Temps		 N
R PLATINUM-
13% RHODIUM
Pt-13% Rh		 PLATINUM
Pt		 NONE
ESTABLISHED		 Thermocouple Grade:
32 to 2642°F
0 to 1450°C
Extension Grade:
32 to 300°F
0 to 150°C		 –58 to 3214°F
–50 to 1768°C		 –0.226
to 21.101		 greater of
1.5°C or 0.25%		 greater of
0.6°C or 0.1%		 Oxidizing or Inert.
Do Not Insert in Metal Tubes.
Beware of Contamination.
High Temperature		 R
S PLATINUM-
10% RHODIUM
Pt-10% Rh		 PLATINUM
Pt		 NONE
ESTABLISHED		 Thermocouple Grade:
32 to 2642°F
0 to 1400°C
Extension Grade:
32 to 300°F
0 to 150°C		 –58 to 3214°F
–50 to 1768°C		 –0.236
to 18.693		 greater of
1.5°C or 0.25%		 greater of
0.6°C or 0.1%		 Oxidizing or Inert.
Do Not Insert in Metal Tubes.
Beware of Contamination.
High Temperature		 S
U COPPER
Cu		 COPPER-LOW
NICKEL
Cu-Ni		 NONE
ESTABLISHED		 Extension Grade:
32 to 122°F
0 to 50°C		         Extension Grade
Connecting Wire for
R and S Thermocouples,
Also Known as RX and SX
Extension Wire.		 U
B PLATINUM-
30% RHODIUM
Pt-30% Rh		 PLATINUM-
6% RHODIUM
Pt-6% Rh		 NONE
ESTABLISHED		 Thermocouple Grade:
32 to 3092°F
0 to 1700°C
Extension Grade:
32 to 212°F
0 to 100°C		 32 to 3308°F
0 to 1820°C		 0 to 13.820 0.5% over 800°C NOT
ESTABLISHED		   Oxidizing or Inert.
Do Not Insert in Metal Tubes.
Beware of Contamination.
High Temperature. Common Use
in Glass Industry		 B
G*
(W)		 TUNGSTEN
W		 TUNGSTEN-
26% RHENIUM
W-26% Re		 NONE
ESTABLISHED		 Thermocouple Grade:
32 to 4208°F
0 to 2320°C
Extension Grade:
32 to 500°F
0 to 260°C		 32 to 4208°F
0 to 2320°C		 0 to 38.564 greater of
4.5°C or 1.0%		 NOT
ESTABLISHED		   Vacuum, Inert, Hydrogen.
Beware of Embrittlement.
Not Practical Below
399°C (750°F).
Not for Oxidizing Atmosphere		 G
(W)
C*
(W5)		 TUNGSTEN-
5% RHENIUM
W-5% Re		 TUNGSTEN-
26% RHENIUM
W-26% Re		 NONE
ESTABLISHED		 Thermocouple Grade:
32 to 4208°F
0 to 2320°C
Extension Grade:
32 to 1600°F
0 to 870°C		 32 to 4208°F
0 to 2320°C		 0 to 37.066 greater of
4.5°C or 1.0%		 NOT
ESTABLISHED		   Vacuum, Inert, Hydrogen.
Beware of Embrittlement.
Not Practical Below
399°C (750°F)
Not for Oxidizing Atmosphere		 C
(W5)
D*
(W3)		 TUNGSTEN-
3% RHENIUM
W-3% Re		 TUNGSTEN-
25% RHENIUM
W-25% Re		 NONE
ESTABLISHED		 Thermocouple Grade:
32 to 4208°F
0 to 2320°C
Extension Grade:
32 to 500°F
0 to 260°C		 32 to 4208°F
0 to 2320°C		 0 to 39.506 greater of
4.5°C or 1.0%		 NOT
ESTABLISHED		   Vacuum, Inert, Hydrogen.
Beware of Embrittlement.
Not Practical Below
399°C (750°F)–Not for
Oxidizing Atmosphere		 D
(W3)

++ Except as further restricted by temperature limits for T/C diameter and insulation tables that follow.

* Not official symbol or standard designation.

** For controlled initial accuracy below 0°C, ask OMEGA's sales Department for a CAL-4 calibration report.

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