Thermocouple is the heat to the hot end of it on the hot medium (Seeback), according to the Seebeck thermoelectric effect size to determine the temperature. The precondition of heat transfer from hot medium to the hot end is that there must be a temperature difference. Therefore, the measured temperature is not the actual thermal medium temperature, that is, there is a temperature measurement error. If we consider the errors of the measurement system of each component, the dynamic error of temperature, air flow and heat exchange effect caused by the error of the measurement error of the actual up to 30 DEG ~50 DEG, and may even exceed 100 degrees, impact on the quality and quantity of the products is great.
Forging furnace, heat treatment furnace machinery factory, industrial furnace and chemical reactors are required to control the temperature (600 DEG C), and some have to strictly control the temperature (the temperature tolerance is less than or equal to 5 DEG C), so it is very necessary to improve the measurement precision of thermocouple. For example, the inaccurate forging temperature of some alloy steel will cause the forgings to be cracked or the range of forging temperature is too narrow, increasing the fire and burning loss. The temperature control of heat treatment is not allowed, which affects the structure and mechanical properties of the metal. The temperature control of the kiln is not allowed, which affects the quality of the burning parts. The chemical reaction is not allowed to control the temperature, and it will be dangerous.
The current automatic temperature control system can eliminate some temperature measurement errors, but can not basically eliminate the temperature measurement error. Because the selection and installation of components in the temperature measurement system is unreasonable, the selection of thermal parameters is inappropriate, and no appropriate measures to reduce the error of the temperature measurement are adopted.