Advantages of capacitive sensors
1) Good temperature stability
The capacitance value of the capacitive sensor is generally independent of the electrode material, which is advantageous for selecting a material with a low temperature coefficient, and the heat generation is extremely small, which has little effect on stability. The resistance sensor has copper loss, which is easy to generate heat and produce zero drift.
2) Simple structure
Capacitive sensors are simple in structure, easy to manufacture and guarantee high precision. They can be made very compact to achieve some special measurements. They can work in harsh environments such as high temperature, strong radiation and strong magnetic fields, and can withstand large temperatures. Change, withstand high pressure, high impact, overload, etc.; can measure ultra-high temperature and low pressure difference, can also measure the magnetic work.
3) Dynamic response is good
Due to the small electrostatic attraction between the electrodes (about 10^(-5)N), the capacitive sensor requires very little energy and can be made very small and thin due to its movable part. Very light, so its natural frequency is very high, dynamic response time is short, can work at a few megahertz frequency, especially suitable for dynamic measurement. Because of its small dielectric loss, it can be powered by higher frequencies, so the system operates at a higher frequency. It can be used to measure parameters that change at high speeds.
4) Non-contact measurement and high sensitivity
Non-contact measurement of vibration or eccentricity of the rotary shaft, radial clearance of small ball bearings, etc. When non-contact measurement is used, the capacitive sensor has an average effect, which can reduce the influence of the surface roughness of the workpiece on the measurement.