A method how to accurately estimate the drift of gravimeter is one of important but difficult problems in the analysis of gravimetric data, especially for data obtained through gravimetric connections which were carried out taking a long duration of time. It was clearly recognized for some gravimeters, in international gravimetric connections along the Circum-Pacific zone performed in 1979-1982, that positive and negative drifts of the gravimeter occurred when the gravimeter was brought from places with large and small gravity values, respectively. It was, however, difficult to conclude which affects the drift of the gravimeter more, ambient temperature or gravity value of measured stations. A similar tendency was found for both gravimeters G-196 and G-605, but the opposite tendency for the gravimeter G-484 through an international gravimetric connection between Japan and China. This fact may suggest that a thermal effect on the gravimeter is more effective on the drift of LaCoste & Romberg gravimeter than a stress relaxation of its spring system.
