Non-contact measurement for profile of different diameter micro/mini holes with capacitance sensor

Now the basic structures of capacitive sensors always use cylindrical fixed electrodes and the measurement for different diameter hole requires different specifications of sensor probe. For the shortfall of the measurement method for hole profile with capacitive sensor, this paper introduces the principle of capacitive sensor for micro/mini hole measurement and the capacitance-based device used in different diameter micro/mini holes’ profile measurement through the structural improvements of the capacitive sensor probe, then simulation and error analysis are conducted. The simulation results indicate the error is less than 5%, and it verifies the feasibility of the profile measurement principle for different diameter hole with capacitance sensor.