SEISMOMETER WITH SYSTEM OF AUTOMATIC PHASE CONTROL OVER PERIOD OF NATURAL OSCILLATIONS Russian patent published in 2002 - IPC

FIELD: measurement technology, gravitational measurements in seismometry, in particular. SUBSTANCE: seismometer has inert mass, capacitive displacement transducer, force pickup coming in the form of multisectional coil, operational amplifier, blocking capacitor, commutation unit, matrix of resistors, generator and circuit forming correction signal comprising comparator, multiinput AND gate, two counters, register and generator of high-frequency oscillations. Inert mass, capacitive displacement transducer, blocking capacitor and one winding of multisectional coil of force pickup form speed feedback circuit. Inert mass, capacitive displacement transducer, operational amplifier, second winding of multisectional coil of force pickup and matrix of resistors form displacement feedback circuit. With change of frequency of free oscillations of seismometer content of counter entered into register changes too. Then resistors of corresponding value are connected by means of matrix of resistors through commutation unit in series with second coil of force pickup changing frequency of free oscillations of seismometer. EFFECT: stabilization of range of frequency of measured seismic disturbances thanks to automatic control over period of natural oscillations of inert mass. 1 dwg