Method and device for generating short narrow-band sound pulses by means of ultrasonic probes

摘要

The main field of application is the non-destructive testing of materials, but the invention can also be used in other fields in which ultrasound is used as a means for a test method. The invention has the purpose of reducing the expenditure hitherto associated with generating short narrow-band sound pulses by means of wide-band resonators and, as a result, provide for high test sensitivity and the evaluation of the test finding by means of AVG diagrams. It is characterising for the invention that the capacity of a mechanically highly damped resonator is connected in parallel and/or in series with an inductance of such a magnitude that this results in a narrow-band sound pulse of predetermined centre frequency. The coils for the probe circuit, the overall circuit diagram of which is shown in Figure 3, are accommodated, together with an electronic device for measuring the actual centre frequency, in a housing which must be connected directly into the line between an arbitrary ultrasonic device and a mechanically highly damped resonator. <IMAGE>