Patent ID: 7770453

Claim:
A method of detecting debris on a material, comprising the steps of: (a) providing a debris detector comprising: a piezoelectric converter unit that transforms electrical energy into mechanical motion at an output; a coupler having a first end and a second end, the first end being operably associated with the converter output so as to transmit the mechanical motion produced by the converter unit, the second end being attached to the material, and, a pulser/receiver operably connected to the converter unit, the pulser/receiver being operable to actuate the piezoelectric converter and receive electronic signals generated by the piezoelectric converter; (b) sending a first electronic signal from the pulser/receiver to activate the piezoelectric converter, thereby transmitting mechanical motion through the coupler and into the material; (c) receiving reflected mechanical motion through the coupler and into the converter, thereby generating a second electronic signal by the converter that is received by the pulser/receiver; (d) comparing an actual value associated with the second electronic signal to a known value.