Study on the dynamic temperature feature of a ratiometric principle based digital angular sensor

The paper described a design of digital angular sensor with 180deg measurement range, based on ratiometric and capacitive measurement principle, and has a metallic and ungrounded rotor plate. Owing to its structure and measurement mechanism, the sensor has intrinsic reliability and can effectively restrain common mode disturbances, say, temperature, moisture, dust etc., without any additional compensator. Focusing on temperature field with rapid changing rate, experiments were carried out on the prototypes of the sensor. The results show that when the environmental temperature climbs sharply from -15degC up to +65degC at about 6degC /min rate, the maximal peak-peak temperature drift of the prototypes is 0.085%/10degC. During the whole experimental period, the maximal steady temperature drift is 0.07%/10degC and the standard uncertainty is less than 0.1%. In addition, for a wide-temperature-range experiment (-30degC~+80degC) with the same change in rate, the maximal peak-peak temperature drift is less than 0.2%/10degC. It goes without saying that its restraining-temperature-drift ability is better than that of mainstream products based on differential measurement principle.