For the measurement of piezoelectric deformations of quartz and tourmaline plates an amplifying lever system was designed and built. A lever ratio of 1864 to 1 combined with an optical interference method of measuring the motion of the long end of the lever makes it possible to detect a displacement of the short end of only 0.15 Angström unit. The changes in thickness of quartz plates about two mm thick were measured with potential differences up to 500 volts between the electrodes on the faces of the plates. The piezoelectric constant of quartz found by this method using the converse piezoelectric effect is in fair agreement with the results of previous observers using the direct effect. The quartz crystals were found to be very non-uniform even though they appeared homogeneous in polarized light. The chief difficulty found in the use of the apparatus is in eliminating disturbance from vibrations.
Proceedings of the Iowa Academy of Science
©1933 Iowa Academy of Science, Inc.
"Piezoelectric Measurements of Crystals with a High Sensitivity Lever,"
Proceedings of the Iowa Academy of Science, 40(1), 152-153.
Available at: https://scholarworks.uni.edu/pias/vol40/iss1/81