关键词: 小深孔, 电容探针, 传感器标定：驱动电缆

Abstract:

A system, which used the capacitance sensor to measure the aperture of small blind holes, was studied. A capacitance probe with small diameter was used as the sensor. The capacitance instrument converted the change of the aperture in to the change of voltage signals which can be inputted into a computer through the USB interface to get processed. The working principle of the capacitance sensor and the electronic circuits of the capacitance instrument were discussed. The design scheme was also disserted as the system using the capacitance sensor to measure the aperture of small holes. The calibration of the sensor was done on the small blind holes with 3mm and 7mm aperture. From the analyzed experimental data, the resolution is 005μm, and the standard deviation of the experiments is within 05μm. 

Key words: small deep hole, capacitance sensor, calibration of sensor, driving cable