For which application is a thermocouple type J suitable?
A type J thermocouple (Fe-CuNi or iron/copper-nickel) according to DIN EN 60584 is suitable for applications at high temperatures in vacuum, oxidizing (air), reducing or inert atmosphere (inert gases). The standardized temperature range of the type J thermocouple is -180°C to +700°C.
Type J thermocouples have an operating temperature range, described in the standard DIN EN 60584, from -40 to +750°C (in class 1) and a limiting deviation of ±1.5°C or 0.40%. The temperature range of a type J thermocouple is -40 to +750°C in class 2. The temperature deviation (limit deviation) is ±2.5°C or 0.75%.
What is the structure of a type J thermocouple (Fe-CuNi)?
The legs of a type J thermocouple (positive leg: black; negative leg: white) are made of the following materials:
Type J (+) leg (Fe):
99.5% iron, approx. 0.25% manganese, approx. 0.12% copper, rest: other impurities
Type J (-) leg (CuNi):
55% copper, 45% nickel approx. 0.1% cobalt, iron and manganese
An overview of other thermocouples for thermocouples with general properties, the temperature range, material composition as well as advantages and areas of application can be found in the table Overview thermocouples. Information on the electrical voltage of thermocouples can be found in the table Thermoelectric voltage.
Color code |
| |||||
|---|---|---|---|---|---|---|
material |
temperature range | Application | Limit deviation | Application temperature range in class 2 | Limit deviation | |
|
| -180°C/+700°C |
| ±1,5°C or 0,40% | -40 to +750°C | ±2,5°C or 0,75% |
Types and designs of thermocouples type J (Fe-CuNi)
Depending on the application and temperature range, type J thermocouples can be used with a connection cable, a thermocouple plug, a protection tube and a connection head. In the following overview you will find common thermocouples or sheathed thermocouples type J, which are often used.
