Temperature and stress-strain state monitoring of isolation switch based on surface acoustic wave sensing technology
Based on surface acoustic wave(SAW)theory and perturbation theory,this paper proposes and develops a differential SAW temperature-strain composite sensor composed of three resonators for the first time.Two SAW resonators of AT cut and XY cut were simulated by finite element analysis software.According to their frequency-strain response and frequency-temperature response,a temperature-strain sensor capable of temperature compensation and strain compensation was designed and developed.The stress measurement sensitivity is 100 Hz/με,and the temperature measurement sensitivity is 80 kHz/℃.The sensor has been successfully applied to the state monitoring of the isolating switch.Experimental data at testing ground show that the sensor can detect the temperature and strain of the isolating switch's fingers,which can effectively discriminate the working state of the isolating switch.