J Type Thermocouple:

Element Combination:

Positive Leg:  Iron

Negative Leg:  Copper – 45% Nickel (constantan)

Temperature:

0-760 ºC 

32-1400 ºF

Application:

• Type J thermocouple is a very common and general purpose thermocouple
• It has smaller temperature range and a shorter lifespan at higher temperatures
• It is suitable for vacuum, reducing, or inert atmospheres.
• It has Oxidizing atmosphere with reduced life. 
• Iron oxidizes rapidly above 538 °C [1000 °F] so only heavy gauge wire is recommended for high temperature. 
• Bare elements should not be exposed to sulphurous atmospheres above 538 °C [1000 °F].