| 摘要 |
<p>In an acoustic bond logging tool, top and bottom transmitters (30, 36) are provided with a pair of spaced receivers (32, 34) therebetween. A multiplexer (50) including an output to a high speed analog to digital converter (52) is time multiplexed to digitize both receiver output signals obtained from the same transmitted pulse. By damping the transmitted pulse to provide first or second peaks in the transmitted burst and gating the receiver signals through multiplexing, the corresponding received peaks can be located and amplified. With a stepped digit gain control, the analog to digital converter (52) can be operated with greater resolution and improved accuracy whereby large, non clipped signal peaks are provided for digitization, thereby indicating attenuation of the transmitted signal, thereby indicating quality of the acoustic bond.</p> |
