Final rept. 15 Jun 1968-15 Jun 1969
CALIFORNIA UNIV BERKELEY DEPT OF MATERIALS SCIENCE AND ENGINEERING
Pagination or Media Count:
Elastic wave theory predicts that the elastic waves generated by an earthquake and other seismic events include a measurable component of horizontal elastic rotation. Several rotational seismometers have been designed to measure this rotational component. The first design consisted of a large inertial ring of mercury terminated in a coaxial set of stand pipes housing capacitive transducers to sense the displacement of the mercury in the stand pipes. The second design consisted of a continuous inertial ring of water with a thermistor transducer to detect flow within the pipe. The third design consisted of a continuous inertial ring of water with a thin paddle placed in the path of flow. Problems encountered involved spurious signals due to a flexible pipe, electronic noise and drift, temperature stabilization, and moisture penetration into the transducers. The capacitive transducer seemed to be the most promising, and experimentation is continuing using this transducer within a rigid steel pipe.