抄録
The drift correction often comes into question when gravity measurements are made by use of a spiral spring-type gravity meter. In this paper, the drift data of the LaCoste and Romberg gravity meter G 34 of the Earthquake Research Institute, Tokyo University, is discussed. The writer has observed drift once a day for about eight years since this gravity meter was purchased in 1963. The drift data show evidently annual changes, the amplitude of which exceeds 1 mgal. The drift-rate is large in the winter season but small in the summer. The correlation coefficient between the drift-rate and room tem perature is -0.82. On the other hand, the new type LaCoste and Romberg gravity meter G 210 equipped with continuous temperature control mechanism was purchased on September 1969. The drift-rate of G 210 seems relatively small as compared with that of G 34.
