A Study on Electrical Characteristics of a Capacitive Pressure Sensor Element to Measure the Pressure of Refrigerant of Air-Conditioner

Title & Authors
A Study on Electrical Characteristics of a Capacitive Pressure Sensor Element to Measure the Pressure of Refrigerant of Air-Conditioner
Choi, Ga-Hyun; Chung, Woo-Young; Choi, Jung-Woon; Kim, Si-Dong; Min, Joon-Won;

Abstract
The purpose of this study is to optimize the design of a capacitive pressure sensor element using the simulation of electrical characteristics. The simulation of the ceramic sensor diaphragm ($\small{Al_2O_3}$) was performed by permitting pressure to change the curvature of the diaphragm. The pressure capacitance ($\small{C_P}$) was increased from 19.63 pF to 15.26 pF by applying pressure because the distance between the electrodes has been changed from $\small{30{\mu}m}$ to $\small{15{\mu}m}$. When the thickness of the diaphragm was changed to 0.46~0.52 mm, a larger capacitance change showed in accordance with the reduced thickness, which means an increase of sensitivity. However, considering the viewpoint of the signal linearity, it was selected for the optimum thickness of the diaphragm to 0.50 mm. The designed sensor element based on simulated results was tested to measure the output characteristics. Comparing of simulated and measured results, there was a margin of error of approximately 2%.
Keywords
Pressure sensor;Capacitive type;Air-conditioner for automobile;Pressure of refrigerant;
Language
Korean
Cited by
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