Analysis of theoretical error of phase-discrimination capacitive sensor

Since being introduced into domestic measurement field during the 1980´s, grating-shape capacitive sensors have played an important role in due to their high accuracy and low cost compared to ordinary capacitive sensors and grating respectively. To better arrest the error of this sensor, we primarily employ Matlab to analyze theoretical error in order to calculate optimum ratio of reflecting electrode and emitting electrodes. Based on our analysis, we are able to find out that the optimum ratio is 1.5∶1 and thus several structural designs of capacitive sensor are given in this paper. Simulations indicate that theoretical error concerned in this document is better reduced by our designs than that by classic structure.