GRADIOMETRIC SEISMIC RECEIVER Russian patent published in 2012 - IPC G01V7/10 

FIELD: physics.

SUBSTANCE: gradiometric seismic receiver is a physical pendulum with three degrees of freedom on angular oscillations relative the suspension point. Its working body is a dumb-bell arm. Angular oscillations of the pendulum relative three axes are picked up by angle sensors. The position of the pendulum on the azimuth coordinate is controlled by an automatic control system whose actuating element is a torque sensor, and the feedback element is an angle sensor between the arm and the housing of the device. The effective length of the pendulum corresponds to oscillations in the frequency range 0.1-1 Hz, and its value is determined by the ratio between the Q-factor of the resonance tuning of the physical pendulum circuit and the double ratio of the square of the effective length to the square of the greatest radius of inertia of the arm.

EFFECT: ensuring synchronism of resonant oscillations of the pendulum on both coordinates, which enables to obtain a signal containing forecast features of an earthquake.

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