Capacitive sensor high-precision measurement system

Capacitive grating sensor can be used to measure the length, as its capacitance changes with the shift difference. This sensor adopt the way of cyclical altering coupling area to measure, which void defect that are small measuring range and non-linear output. Through to accommodated the principle and structure of Capacitive grating sensor, This article designs one kind of closed loop feedback amplitude discrimination Capacitive measuring system, In system, Digital succession is programmed by CPLD while analysing about error and produces reason is achieved. On the basis of the experimental data, the indication error is less than 3um. the measuring range is from 0 to 200 mm.