J Type Thermocouple

Key Features

Construction: Made of a positive leg of Iron (Fe) and a negative leg of Constantan (a copper-nickel alloy).

Temperature Range: Standard range is -40°C to 750°C, but it can be used for short durations up to 1,000°C.

Atmospheric Suitability: It’s ideal for reducing atmospheres (where oxygen is low, and reducing gases are present) or vacuum applications, but it degrades rapidly in oxidizing atmospheres above 550°C.

Sensitivity: Has a sensitivity of approximately 50 µV/°C, which contributes to its precision.

Durability & Lifespan: It is considered sturdy and cost-effective but has a shorter lifespan at high temperatures compared to other types like Type K.

Curie Point Limitation: The iron in the positive leg has a Curie point at around 770°C, which limits the thermocouple’s maximum operating temperature.