| 摘要 |
PURPOSE:To display a trouble a preset time later, when there is no output from a reverberation extracting circuit, by extracting the reverberation in the ultrasonic case so that the frequency from oscillating an ultrasonic head is controlled by the extracted frequency. CONSTITUTION:The oscillatory output from an oscillator 4 is fed through a gate circuit 5 to an ultrasonic head 1 for a time period determined by a preset period thereby to generate ultrasonic waves. After the head 1 is driven, a microprocessor 7 feed its command signals to a reverberation extracting circuit 2 for the time period, during which the reverberation waves are generated, and an automatic frequency adjusting circuit 3 effects such contol as to make the frequency of the output signals of the oscillator 4 coincident with that of the reverberation waves, thereby to drive the head 1. On the other hand, the reflected signals from the refrence side of the head 1 and from the object enter a wave receiving amplifier 6, but if there is no output from the circuit 2 no input is fed to the amplifier 6. As a result, a tire 9 is not reset, so that the output is fed to a trouble display device 10 a preset time later thereby to display the trouble. |
