Surface acoustic wave dust-deposition sensor

Surface acoustic waves travel by interaction between the atoms near the surface of a solid, with the consequence that attenuation of these waves can be sensitive to dust accumulation on the surface across which they propagate. This report reviews the relevant acoustic theory and its application to the design of a system for evaluating the feasibility of using the attenuation of surface acoustic waves for monitoring surface dust-deposition rates. The monitoring system is described, and the results of preliminary experiments are given. The results indicate that multireflected surface acoustic waves are attenuated sufficiently by a specified, maximum dust-layer surface density of 3.10 x 10(5) mg/m(2) (200 mg/in(2)) and that this approach should be investigated further for application in high-temperature, corrosive-atmosphere, coal-conversion process applications.