Abstract: A method and apparatus for inspecting a wall of a mechanical structure including obtaining an infinite response from a sample material having a front face, a thickness, and a back wall, by transmitting into a sample material an ultrasonic wave having a frequency and duration and being generated by one or more transducers, wherein the thickness of the sample material is sufficiently great that only a wave corresponding to the front face of the sample is received back; transmitting an ultrasonic wave generated by one or more transducers into the wall of a mechanical structure to be inspected at a time (T), wherein the ultrasonic wave has the same frequency and duration as the ultrasonic wave transmitted into the sample material; receiving a response signal back from the wall to be inspected; and correlating the response signal to the infinite response, thereby creating correlated data.

Abstract: A robotic ultrasonic inspection vehicle is provided with one or more transducers which are driven by a long, broadband excitation pulse for insonifying a sample subject to inspection. The long, broadband excitation pulse can be chirped. The robotic vehicle also can include a drive circuit for coupling the excitation pulse to the transducer. Data associated with the excitation pulse is used to gate off the drive circuitry at an appropriate time. The robotic vehicle may traverse a combustion prone region and therefore electrical parameters may be limited to intrinsically safe levels. However electrical parameters may safely be converted to higher levels so long as the conversion is inhibited to occur only after the vehicle has left a combustion prone region and entered a region of minimal risk of combustion.