Possible non‐linear effects in TRG‐1 Earth tide meters

Calibration of Geodynamics TRG‐1 and similar non‐nulling earth tide gravimeters indicates that the calibration constant varies with beam position by as much as 20%. The resulting non‐linearity can introduce errors in the determination of the gravimetric factor in the order of 1%. This error level is significant in the determination of gravity tide admittances and in interpreting earth tide measurements for ocean tide effects and regional geology.