Abstract: A configuration flexible computer-controlled ultrasonic diagnostic test equipment arrangement for examining large turbine rotors incorporates improved ultrasonic signal "pulser-receiver" circuitry that is used to drive one or more an ultrasonic transducers and to receive and amplify ultrasonic returns from a specimen under test. The improved pulser-receiver circuitry comprises both an ultrasonic pulse generating circuit and an associated ultrasonic return signal linear amplification circuit. The pulse generating circuitry and the ultrasonic return signal amplification circuitry are modular and functionally independent of each other and, consequently, may be used together in the testing system or as stand-alone instrumentation. Overall ultrasonic diagnostic system flexibility is significantly enhanced by providing improved pulser-receiver circuitry with digitally driveable computer control inputs in addition to manual controls to enable selecting initial parameters and transducer position settings.

Abstract: An eddy current probe, excitable at frequencies equal to or greater 7 mhz., includes a substantially planar, spiral-like, unilaminar coil mounted on an insulative substrate. A protective layer covers the coil and is adopted to present only a minimal mechanical barrier between the coil and a region of material under test. The coil is a continuous run of copper having an effective diameter no greater than 2 mils. The coil, substrate and protective layer are a printed circuit board. A method of detecting flaws is also disclosed.

Abstract: An eddy current probe, excitable at frequencies equal to or greater 7 mhz., includes a substantially planar, spiral-like, unilaminar coil mounted on an insulative substrate. A protective layer covers the coil and is adapted to present only a minimal mechanical barrier between the coil and a region of material under test. The coil is a continuous run of copper having an effective diameter no greater than 2 mils. The coil, substrate and protective layer are a printed circuit board. A method of detecting flaws is also disclosed.