How to choose the thermocouple of the experimental electric furnace?

At present, there are several types of thermocouples commonly used in industrial production, such as B, S, K, E, N, J, etc. When purchasing a thermocouple, you should choose the thermocouple with the same graduation number as the measuring instrument. In the case of meeting the requirements of the process regulations, if multiple temperature measuring instruments are used at the same time, thermocouples with the same graduation number should be selected as much as possible to prevent the mixing of thermocouples with different graduation numbers and measuring instruments due to artificial reasons, resulting in quality accident.