| 摘要 |
PURPOSE:To save energy and to improve portability by using an ultrasonic pulse burst wave as a measuring wave and constituting a measuring system so as to be set up to the optimum frequency condition. CONSTITUTION:A transmitting amplifier 14 is turned to the driving status by an output 18 of a timing pulse generating part 15 only for the ON time of the output 18 to drive a probe 1. An interference voltage of a transmitting wave outputted from the probe 1 is applied to a vibration speed detection part 12. The detection part 12 detects a motional voltage proportional to the vibration speed of the interference wave received by the probe 1 and the detected output is fed back to a band filter 13 and amplified by the amplifier 14 to drive the probe 1. The output 19 of the generation part 15 is set up so that a receiving amplifier part 16 is ON only for a time band receiving an ultrasonic echo in a bumb. |
