A Discussion on the measurement and interpretation of changes of strain in the Earth - A technique for the precise calibration of continuously recording gravimeters

Abstract

A prototype device to calibrate recording Earth tide meters of the TRG-1 variety has been constructed and demonstrated to operate satisfactorily. The calibration is effected by subjecting the gravimeter to an external sinusoidal acceleration of approximately 3 [rm/s2. The magnitude of the applied acceleration, which is determined from a record of the gravimeter’s displacement, is compared directly with the gravimeter’s response. The prototype was limited to a driving frequency of 0.01 Hz. The reconstruction of the calibrator to permit operation at frequencies down to 0.001 Hz is discussed. A calibration precision of 0.1% was achieved with the prototype.