| 摘要 |
An ultrasonic logging apparatus is provided with a receiver for receiving acoustic returns of varying amplitudes and a digitizer for digitizing the acoustic returns. The receiver utilizes the same transducer as the transmitter, and has input switching protection to protect the amplifiers from the transmitter signal. The receiver amplifiers have gain switching, utilizing junction field-effect transistors to produce rapid gain switching during an acoustic return. The gain switching allows the digitizer to digitize with satisfactory resolution.
|
