抄録
A second quartz plate(B)was connected between grid and cathode of the vacuum tube of a Pierce oscillator circuit employing the control quartz(A)connected between plate and grid of the vacuum tube(in this experiment 42 or 6L6A). A was an oscillator quartz of high precision and low temperature coefficient, and B an x-cut transducer quartz used in the ultrasonic interferometer, both crystals being of nearly the same frequency(in this experiment 1. 43Mc/sec or 0. 47Mc/sec)with a frequency difference of several hunhred cycles per sec. This circuit worked with high sensitivity and good frequency stability for liquid interferometers, when used with plate voltage of 70〜100volts. The deviation of frequency by insertion of the transducer quartz was usually less than 100cycles/sec and always less than 0. 02% of the frequency value.
