J type thermocouple

Type J thermocouple is also a subtype of base metal thermocouple with iron-constantan as its constituents, is also a cheap metal thermocouple. This thermocouple also has great accuracy and reliability almost equal to K type thermocouple but the temperature range and life span are much shorter than the K type thermocouple. This limits its use to a certain level but j type is still 2nd most commonly used thermocouple due to low price. The temperature range is between -200 ~ 1200 ℃, but the normally used temperature range is usually 0 ~ 750 ℃,J thermocouple whereas the accuracy and risk factor are exactly the same as for K type thermocouples i.e 75% and 0.4% respectively. J type thermocouples are not ideal for use in a damp environment since they are less resistance to oxidization.J thermocouple is easy to identity because the cables has a specific black coding colour.

J Thermocouple usage

• They are most likely preferable in plastic industries
• They are also applied in inert material temperature measurement
• Vacuum applications to monitor fluids temeprature

J thermocouple features

1. J-type thermocouple has the advantages of good linearity,
2. Large thermo-electromotive force
3. High sensitivity
4. Good stability
5. Cheap price industrial temperature sensors

J-type thermocouples can be used in vacuum, oxidation, reduction and inert atmospheres, but the positive electrode iron oxidizes faster at high temperatures, so the use temperature is limited, and it cannot be used directly in a sulfurized atmosphere at high temperatures without protection.