Thermocouple Wire Types

 

Type Conductors ANSI Color Coding IEC 584-3 Color Coding Temperature Range Comments
(+) Leg (-) Leg TC Grade Extension Grade TC TC Grade Intrinsic. Safe Min Max
 

J

Iron Constantan -210°C

/

-346°F

1200°C

/

2193°F

Reducing, vacuum, Inert. Limited use in oxidizing at high temperatures. Not recommended for low temperatures
 

K

Chromel Alumel -270°C

/

-454°F

1372°C

/

2501°F

Clean oxidizing and inert. Limited use in vacuum or reducing. Wide temperature range, most popular calibration.
 

T

Copper Constantan -270°C

/

-454°F

400°C

/

752°F

Mild oxidizing, reducing vacuum or inert. Good where moisture present. Low temperature & cryogenic applications
 

E

Chromel Constantan

-270°C

/

-454°F

1000°C

/

1832°F

Oxidizing or inert. Limited use in vacuum or reducing. Highest EMF change per degree.
 

N

Nicrosil Nisil -270°C

/

-450°F

1300°C

/

2372°F

Alternative to Type K. More stable at high temps.
 

R

Copper Alloy 11 -50°C

/

-58°F

1768°C

/

3214°F

Oxidizing or inert. Do not insert in metal tubes.
Beware of contamination. High temperature.
 

S

Copper Alloy 11 -50°C

/

-58°F

1768°C

/

3214°F

Oxidizing or inert. Do not insert in metal tubes. Beware of contamination. High temperature.
 

B

Platinum- 30%
Rhodium PT- 30%
Platinum- 6% Rhodium Pt- 6% 0°C

/

32°F

1820°C

/

3308°F

Oxidizing or inert. Do not insert in metal tubes. Beware of contamination. High temperature common use in glass industry