Constant temperature control system of standard capacitors

This paper describes a constant temperature control system for high accuracy standard capacitors developed by NIM. The system includes a constant temperature slot and temperature control circuit. Structure, material and some techniques on reducing the heat transfer of the constant temperature slot are discussed. The temperature control circuit based on PID automation control technology is used to control the slot internal temperature. The system has the resolution of 0.002 °C and the fluctuation of ±0.01 °C, and can reduce capacitance variation of the standard capacitors when the environment temperature changes. The system can improve the standard capacitors with higher accuracy and better stability.