What are the advantages and limitations of a thermocouple?

What are the advantages of a thermocouple sensor?

There are many reasons why you would choose a thermocouple for your application, these include:

  • Thermocouples can be used at very high temperatures
  • Thermocouples can be used in demanding environments
  • Thermocouples have high reproducibility
  • Thermocouples have a fast response time
  • Thermocouples are very accurate at a wide operating range
  • Thermocouples have extreme durability
  • Thermocouples are self-powered, so they do not require a current or voltage source
  • Thermocouples can withstand high vibrations

What are the limitations of a thermocouple?

Even though a thermocouple probe is the perfect choice for many applications, there are some limitations including the following:

  • Thermocouples are not as accurate as RTD sensors in a certain set temperature range
  • Thermocouples are susceptible to drift over time
  • Thermocouples, when badly insulated, are vulnerable to corrosion
  • Thermocouple signals are not perfectly linear

Common thermocouple wire types

Click on the type for more information.

Type K, Nicr-Ni thermocouple, for temperature ranges -270°C ..+1260°C

Type N, NiCrSil-NiSil thermocouple, for temperature ranges -270°C ..+1260°C

Type J, Fe-CuNi thermocouple, for temperature ranges -210°C .. +750°C

Type E, NiCr-CuNi thermocouple, for temperature ranges -270°C .. +900°C

Type T, Cu-CuNi thermocouple, for temperature ranges -270°C .. +370°C

Type S, Pt10%Rh-Pt thermocouple, for temperature ranges -0°C..+1600°C.

Type R, Pt13%Rh-Pt thermocouple, for temperature ranges -0°C..+1600°C.

Type-B, Pt30%Rh-Pt6%Rh thermocouple, for temperature ranges -0°C..+1600°C.

Type C and Type D, Thermocouple Wire Tungsten Rhenium Alloy, for temperature up to 2871°C.

What is the highest temperature thermocouple?

High temperature thermocouples, also called exotic thermocouples, are used in applications where
base metal thermocouples cannot be used because of extreme temperatures up to 2200°C and
hazardous environments. The exotic thermocouples can be used in vacuum, inert, oxidizing and reducing.

Determining which is the highest is actually not as simple as it seems. Learn more about high temperature thermocouples.