Types of Thermocouple
We have tried to list all the type of thermocouple available for use.
We have tried to list all the type of thermocouple available for use.
Why the need for different Thermocouple?
The behaviour of metals when put to temperature gradient opened a new door to measure extreme high temperatures.At the same time explorations were made to figure out a way to measure extreme low temperatures. All this lead to indepth study of thermoelectric effect. It was later discovered that one specific material pair can not be used for different measurement windows. Some materials worked excellent for higher temperatures while some worked excellent at sub zero temperatures and were perfect for cryogenics setups.
It was very difficult for manufacturers and users to co-ordinate with each other only by specifying composition to be used for the sensing leads. The naming convension was established for different thermocouple that worked excellent at different temperatures
Thermocouple Types
K Type Thermocouple
Conductor (chromel–alumel)
Working Temp: −200°C to +1350°C
Chromel (+), Alumel (-)
J Type Thermocouple
Conductor (Iron–Constantan)
Working Temp: −40 °C to +750 °C
Iron (+), Constantan(-)
T Type Thermocouple
Conductor (cu–constantan)
Working Temp: −200 to 350 °C
Copper(+), Constantan(-)
R Type Thermocouple
Conductor (PtRh-Pt)
Working Temp: 0 to 1600 °C
PtRh(+), Pt(-)
N Type Thermocouple
Conductor (Nicrosil–Nisil)
Working Temp: −270 °C to +1300 °C
Nicrosil(+), Nisil(-)
B Type Thermocouple
Conductor (PtRh-PtRh)
Working Temp:50 °C to 1800 °C
PtRh(+), PtRh(-)
E Type Thermocouple
Conductor (chromel–Eureka)
Working Temp: −50 °C to +740 °C
Chromel(+), Eureka(-)
M Type Thermocouple
Conductor (NiMo–NiCo)
Working Temp: -50 °C to 1400 °C
NiMo(+), NiCo(-)
S Type Thermocouple
Conductor (PtRh–Pt)
Working Temp: -40 °C to 1700 °C
PtRh(+), Pt(-)
C Type Thermocouple
Conductor (WRe–WRe)
Working Temp: 0 °C to 2329 ℃
WRe5%(+), WRe26%(-)
D Type Thermocouple
Conductor (WRe–WRe)
Working Temp: 0 °C to 2400 ℃
WRe3%(+), WRe25%(-)
G Type Thermocouple
Conductor (W–WRe)
Working Temp: 1000 °C to 2300 ℃
W(+), WRe(-)
P Type Thermocouple
Conductor (PdPtAu–AuPd)
Working Temp: 500 °C to 1400 °C
PdPtAu(+), AuPd(-)