Abstract: A real-time ultrasonic imaging system includes a display which is compensated for the non-ideal characteristics of the search beam profile. Echo responsive electrical signals are provided to a preprogrammed computing means for being processed to compensate for the characteristics of the test probe. The processed signals are displayed as being in focus at all distances from the probe, thereby resulting in an image exhibiting improved resolution.

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: In a pulse-echo ultrasonic test arrangement the back reflected echo acoustic wave signal as well as the scattered longitudinal wave and scattered shear wave signals are utilized in an evaluation circuit for determining more accurately the characteristics of a defect in a workpiece. The evaluation circuit, most suitably, includes a digital computer which in a typical embodiment of the invention is programmed to provide by Fourier transforms the frequency amplitude spectrum and the frequency phase spectrum of the supplied three signals, hence producing six characteristic outputs for a particular defect.

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: Acoustic discontinuity responsive echo signals are compressed using special evaluating means for increasing the resolution of pulse-echo test apparatus. The acoustic discontinuity responsive echo signal undergoes mathematical convolution with a predetermined signal which latter signal is selected for providing that the mathematical product of the Laplace transform of the echo signal and the predetermined signal is unity. The mathematical convolution is performed by a computer, a correlator or an arrangement of delay lines.

Abstract: The invention refers to a measuring circuit for determining the properties of a workpiece, particularly hardness, using the contact impedance method in which a probe resonating at an ultrasonic frequency provided with a workpiece engaging tip is utilized. The measuring circuit uses digital counters for producing a digital count which is the difference between the free-resonant frequency of the test probe and the resonant frequency of the probe when the probe is in forced contact with the workpiece. A read-only-memory (ROM) converts the difference frequency count to a hardness value, such as Vickers or Rockwell. The disclosed arrangement obviates the need for zeroizing the circuit and, hence, is self-compensating in respect to drift and thermal stability.

Abstract: A real-time ultrasonic imaging system includes a display which is compensated for the non-ideal characteristics of the search beam profile. Echo responsive electrical signals are provided to a preprogrammed computing means for being processed to compensate for the characteristics of the test probe. The processed signals are displayed as being in focus at all distances from the probe, thereby resulting in an image exhibiting improved resolution.