Application of a Saw Device for Measuring Rate of Gas Flow. Final Report, April1991-July 1992

摘要

The objective of the program is the development of a compact, high performanceflow meter that will meet the specifications developed by the Gas Research Institute for the next generation of residential gas meters. A solid-state flow meter based on the use of surface acoustic wave (SAW) devices is considered for the application. Attractive features of SAW sensors include high sensitivity, wide dynamic range, direct digital output, small size, and low cost. In the exploratory research phase, a theoretical analysis of the operation of the SAW flow sensor was carried out. This was then used to design a SAW device for the proposed application. Experimental measurements confirm that a single device can measure flow rates over the entire operating range of 118 ml/min. to 95 l/min. The accuracy of the sensor is better than the requirements by at least a factor of 10. Further work that needs to be done in order to reduce power consumption, improve speed of response, and reduce sensitivity to ambient temperature changes is discussed. Work done to date indicates that the SAW technique has good promise for realizing the next generation of residential gas meters.