Thermocouple Wire


What is thermocouple wire?

Type T Thermocouple Wire

Type T
Thermocouple Wire

Thermocouple wire allow temperatures to be measured electronically. A typical thermocouple construction consists of a pair of dissimilar metals that are electrically joined together at the sensing point and connected to a voltage measuring instrument at the other end. When one junction is hotter than the other, the thermal “electromotive” force (in millivolts) is produced that is roughly proportional to the difference in temperature between the hot and cold junctions.

Pelican Wire stocks a wide variety of common thermocouple constructions and can design a custom thermocouple cable to meet your specific need. Some of the most common thermocouple types Pelican Wire provides include:

    • K Type- Chromel and Alumel
    • J Type- Iron and Constantan
    • T Type- Copper and Constantan
    • E Type- Chromel and Constantan
    • N Type- Nicrosil and Nisil

*Pelican Wire can also source B,R, and S type thermocouples upon customers special request*

Common Insulations for Thermocouple Cables

A typical thermocouple cable construction consists of one pair of positive and negative conductor legs that are both insulated and then laid together in a parallel fashion with a protective jacket over the single legs. Pelican Wire can extrude, tape, wrap, serve, and braid various jackets on thermocouple wire (See insulation chart). Pelican Wire also has the capability of jacketing a wire with extremely heat resistance materials which sets us aside from other thermocouple manufacturers. Our insulation temperature ratings vary from 100°C to 1200°C (2200°F). Most insulated thermocouple constructions can be identified by their jacket color or tracer.

Insulated thermocouple wire from Pelican Wire is a reliable and economical solution for temperature measurement at both high and low temperatures. For fast turnaround we stock bare and insulated thermocouple wire (click here to view our thermocouple stocking program). Most of Pelican Wire’s insulated thermocouple wire’s are colored according to ANSI (American National Standards Institute) coding (Click here to view insulation colors). Type J, K, T, and E thermocouples are calibrated with traceability to NIST (National Institute of Standards and Technology) (Click here to view thermocouple calibration tolerances). We supply thermocouple wire as small as 40 AWG. Insulated thermocouple wire can be designed to the customers’ exact specifications including calibration type, wire gauge, and individual calibration requirements.

Thermocouple Wire Applications:

Science, Industry, Instrumentation, Heating Appliances.

Common Thermocouple Wires

Type Singles Normal Operating Temperatures (°F)
J Iron (JP)/ Constantan(JN) 200-1500
K ChromelP(KP)/Alumel(KN) 200-2000
T Copper(TP)/ Constantan(TN) 200-600
E ChromelP(EP)/ Constantan(EN) 200-1600

*Other types available on request

Thermocouple Color Coding

Type Conductors ANSI Color Coding IEC 584-3 Color Coding Temperature Range Comments
Positive Leg Negative Leg Thermocouple Grade Extension Grade Thermocouple Thermocouple Grade Intrinsically Safe Min Max
J Iron Constantan type j ANSI type j ANSI type j IEC Type J IEC -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 Type K ANSI Type K ANSI Type K IEC Type K IEC -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 Type T ANSI Type T ANSI Type T IEC Type T IEC -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 Type E ANSI Type E ANSI Type E IEC Type E IEC -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 Type N ANSI Type N ANSI Type N IEC Type N IEC -270°C/-450°F 1300°C/2372°F Alternative to Type K. More stable at high temps.
R Platinum- 13%
Rhodium- 13%
Platinum Pt None Established Type R/S ANSI Type R/S IEC Type R/S IEC -50°C/-58°F 1768°C/3214°F Oxidizing or inert. Do not insert in metal tubes.
Beware of contamination. High temperature.
S Platinum- 10%
Rhodium PT- 10%
Platinum PT None Established Type R/S ANSI Type R/S IEC Type R/S IEC -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% None Established Type B ANSI Type B IEC Type B IEC 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

Thermocouple Wire Images: