| 摘要 |
An acoustin transducer system for a borehole televiewing apparatus is set forth. In the preferred embodiment, a ceramic circular disc is used and is divided by grooves selected thereon into a set of N concentric rings where N is a whole number integer. Each ring has its own associated transmitter and they are fired in a controlled sequence. Each ring operates as a receiver, and they form output signals which are amplified and controlled delay at the respective delay lines, the several output signals are summed. This assures that the illuminated regions of the borehole is in focus and has a greater depth of field. And a method is also described whereby multiple simultaneous electronically formed acoustic beams are utilized in a differential mode to achieve high spatial resolution in time of flight measurements.
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