Research on Small-Capacity Capacitor Type Sensor Detection Method

Abstract:

In the field of industrial measurement, capacitive sensors are widely used. In many types of capacitive sensors, the output capacitance value range of many sensors is very small, generally between 10pF to 1000pF, but accuracy is usually required to be more than one thousandth. The conventional method of detecting capacitance value is generally the capacitor charge and discharge. By charging and discharging time statistics and calculations, capacitance values are deduced finally. The inherent disadvantages of this method are: (1) Temperature drift of the measurement circuit is large. (2) The spatial magnetic field under special circumstances impact on measurement circuit. (3) Long-term stability of the device will deteriorate. In this paper, a "capacitance measurement method with reference and comparison" is summed up through a lot of measurement experiments of humidity capacitance, that method can eliminate three kinds of defects in the capacitor charging and discharging process.

• Periodical: Advanced Materials Research (Volume 981)
• Pages: 594-597
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.981.594
• Online since: July 2014
• Authors: Wei Tong Hu, Yu Xuan Zhang*, Yan Sun, Wang Sheng Liu, Li Zhong Zhang
• Keywords: Analog Switches, Capacitance Measurement Method with Comparison, Capacitance Measurement Method with Reference, Multivibrator, Small Capacitor Testing

References

[1] T. Scientist, Title of the paper, in Proceedings of the Conference on Smart Sensors and Systems: Technology and Applications (SSS&TA' 2003), Paris, France, 16-19 March 2003, pp.123-127.

[2] Sensors Web Portal (http: /www. sensorsportal. com).