Abstract: In a pulse echo ultrasonic velocity measuring apparatus timing gate signals corresponding to the transit time of search signals traveling through a workpiece are generated. The quantity of fixed frequency pulses occurring during successive timing gate signals is counted and accumulated using time interval averaging techniques until a predetermined quantity of pulses commensurate with the thickness of the workpieces is accumulated. Concurrently, the quantity of search signals required to accumulate the predetermined quantity of pulses is counted. The quantity of search signals counted is commensurate with the acoustic velocity of the workpiece.

Abstract: In a pulse-echo ultrasonic circuit an ultrasonic search signal is periodically transmitted into a workpiece. The ensuing pair of echo signals (entrant and rear surface reflection respectively) are fed to a timing circuit for providing a timing signal responsive to the time interval between the two echo signals. A fixed pulse width pulse generator is triggered responsive to the search signal. The output from the fixed pulse width generator and the timing signal from the timing circuit are selectively fed to a converter circuit for providing an output signal indicative of workpiece thickness or workpiece acoustic velocity. The converter circuit includes adjustable parameters comprising current magnitude and resistance to provide suitable calibration. Similar calibration is achieved also by varying the repetition rate of the search signal.

Abstract: An electrical circuit incorporated in a receiver circuit of an ultrasonic pulse-echo thickness and/or velocity measuring apparatus causes the entrant surface and rear wall responsive video signals to be of equal magnitude and in phase with each other. The provision of echo responsive video signals having equal amplitude and phase results in a measuring apparatus exhibiting improved accuracy while requiring fewer and less expensive circuit components.

Abstract: In a pulse-echo ultrasonic circuit an ultrasonic search signal is periodically transmitted into a workpiece. The ensuing pair of echo signals (entrant and rear surface reflection respectively) are fed to a timing circuit for providing a timing signal responsive to the time interval between the two echo signals. A fixed pulse width pulse generator is triggered responsive to the search signal. The output from the fixed pulse width generator and the timing signal from the timing circuit are selectively fed to a converter circuit for providing an output signal indicative of workpiece thickness or workpiece acoustic velocity. The converter circuit includes adjustable parameters comprising current magnitude and resistance to provide suitable calibration. Similar calibration is achieved also by varying the repetition rate of the search signal.

Abstract: This invention refers to an ultrasonic pulse-echo nondestructive test method and apparatus for causing the axis of an ultrasonic energy search beam path transmitted from an ultrasonic transducer probe to a workpiece to be maintained normal to an irregularly contoured workpiece entrant surface. Electrical circuit means measure and compare the echo signals reflected from the workpiece and cause the search probe to be positioned to maximize the amplitude of the received signals.