Digital recording of ultrasonic signals

Ultrasonic measurements are used in the petroleum industry for determination of compressional and shear wave velocities, energy absorption, and mechanical properties of sedimentary rock samples as an aid to interpretation of seismic and logging data. A computer-controlled ultrasonic system for digital recording of ultrasonic signals has been constructed at Amoco Production Company, Research Center. The basic electronic system consists of a minicomputer, teletypewriter, tape drive, Nicolet digital oscilloscope, an RF source, and a special interface built at the Research Center. The construction and operation of the system are discussed, including a technique using two independent triggers to increase the sampling rate from the 0.5 µsec capacity of the oscilloscope to 0.1 µsec.