The seismograph described has a nearly uniform response to ground oscillations whose periods he between 1.5 s and 12 s, which is the range of particular interest for research on microscisms generated by sea waves. The seismograph consists of a 1 s pendulum which measures ground acceleration over the range of frequencies of interest, and an electronic circuit performing double integration to give a signal proportional to ground displacement. The 1 s pendulum has negative feedback which allows simple damping arrangements and easy absolute calibration, as well as improving stability and linearity. A horizontal-component instrument has been built, but the principle should be equally applicable to measuring the vertical component.
No takes yet. Share an insight, caveat, or question.
M. J. Tucker (1958) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: