초록

A method and device for generating acoustic pulses, preferably ultrasonic, and the use of such pulses, more particularly for non-destructive material testing. The acoustic pulses are produced by a modulation or multiplication technique.

대표청구항 ▼

In a method of generating acoustic pulses, preferably in the ultrasonic region, wherein an acoustic transducer is excited by voltage pulses, said acoustic pulses subject to Fourier integral analysis to determine whether a desired frequency spectrum has been achieved, the improvement comprising the s

In a method of generating acoustic pulses, preferably in the ultrasonic region, wherein an acoustic transducer is excited by voltage pulses, said acoustic pulses subject to Fourier integral analysis to determine whether a desired frequency spectrum has been achieved, the improvement comprising the steps of: providing a monochromatic a.c. voltage train at a desired test frequency; providing at least one voltage pulse; producing pulses for exciting the transducer by amplitude modulation or multiplication of said monochromatic a.c. voltage train (the fundamental oscillation) by said voltage pulse (the modulation oscillation); and adjusting said voltage pulse to have a frequency, shape, exponent and duration so that the corresponding Fourier integral of the fundamental oscillation, the modulation oscillation, transducer characteristic and transfer terms associated with the signal path, provide a desired frequency spectrum for the acoustic signal.