Type J Thermocouples

-40°C to 750°C

Type J thermocouples, or iron–constantan thermocouples have a quite narrow range (from −40 °C to +750 °C) but have a higher sensitivity of about 50 µV/°C. The upper limit of this type of thermocouple is determined by the Curie point of the iron, which is 770 °C.