Title: Peak accelerograph

Abstract: A three-axis instrument for recording peak accelerations in earthquakes and like kinds of shocks. Recording is by scratches made by hard styli on small metal record plates. No power source and no maintenance are required. The seismic recording elements have novel configurations of mass, spring, and lever arm which permit improved combinations of sensitivity and natural frequency for any given magnitude of stylus friction. For example, a sensitivity of 0.25 cm per g with a natural frequency of 32 Hz may be attained, where error due to a stylus frictional force of 70 mg is less than 1 percent of full-scale. Both hydraulic and magnetic dampers are employed. The latter also provide motional electrical signals for use in calibration.

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Inventors: Engdahl, Paul D. (Costa Mesa, CA, US)

Application Number: 591136
Filing Date: 1975-06-27
Publication_date: 1976-08-10
Assignee:
Primary Class(es): 346/7 73/514.12, 73/514.14, 73/514.38, 346/77R, 346/139R
Other Classes:
US Patent Ref:

2959459	Nov, 1960	Ryan	346/7.
3740757	Jun, 1973	Engdahl	346/7.
3795006	Feb, 1974	Engdahl	346/7.

Other Refs:
Primary Examiner: Hartary, Joseph W.
Assistant Examiner:
Attorney: Fleming; Lawrence