SURFACE ACOUSTIC WAVE SENSORS FOR TEMPERATURE AND STRAIN MEASUREMENTS

It is highly desired to develop an inexpensive, wireless embedded sensor system that can provide high-bandwidth measurements of temperature and pressure inside a pipeline for rocket propulsion test applications. The fuel is generally liquid hydrogen and liquid oxygen, which must be kept at cryogenic temperatures. The environment places additional requirements on the design of sensors that is beyond the scope of most available products. Surface acoustic wave (SAW) technology has received considerable attention for harsh environment applications. The ultimate goal of our research is to develop a SAW sensor system for temperature and pressure sensing in the cryogenic environment. In this paper, the temperature testing of the SAW sensor was finished from 30 to 80 degrees C. The strain testing was performed at room temperature. The results have shown that the temperature coefficient of the delay (TCD) at the room temperature is around 74.4 ppm/degrees C. The Strain coefficient of delay (SCD) of the testing result is 0.38 ppm/mu. at room temperature.