Temperature Characteristics of Capacitance Diaphragm Gauge

Capacitance Diaphragm Gauge (CDG) is a type of sensor commonly used under low vacuum with high accuracy and stability. Temperature is one of the most important factors affecting its measurement accuracy. When the ambient temperature changes, the measurement results of CDGs will also drift accordingly. We experimented with the effect of temperature on CDGs and quantified the measurement errors of heated and unheated CDGs in the environment of −30℃~50℃. The experimental results show that the measurement results of the heated CDGs are stable at the rated temperature 0℃~45℃, and the measurement accuracy will deteriorate if the temperature exceeds this range. The error caused by the temperature for the unheated CDG is relatively large. The temperature-pressure error surface proposed in this paper can effectively reduce the measurement error of the unheated CDG and improve its accuracy.