| 摘要 |
<p>The transducer employs a ceramic disc which, when excited by a d-c pulse, vibrates in its planar resonant frequency mode. The sensitivity is selectively increased for the second positive half cycle of the transient oscillation of the disc. The selectively improved transient response is used to greatly increase the precision of measurement of the time interval for a transient pulse of ultrasonic energy to travel the distance between an ultrasonic transmitter and an ultrasonic receiver.</p> |
