Abstract
Precise gravity survey was carried out at specially selected stations, where gravity difference from the Gravity Reference Station of Geophysical Institute of Kyoto University is smaller than about 4 mgal, distributed in the Kinki District, by means of 3 LaCoste & Romberg gravimeters (model G) in November 1970. Back and forth measurement was adopted, step by step, in order to determine the drift of each gravimeter as accurate as possible in the survey. But the results obtained were not more accurate than those by an ordinary gravity survey. On the other hand, an experiment for investigating the characteristics of LaCoste & Romberg gravimeters due to vibrations was made under the following conditions: (1) Gravimeters were shaken by a running motor-car. (2) Gravimeters were taken in and out their carrying cases. (3) Gravimeters were fixed at the station. The results obtained through the present investigations are as follows: (1) Reliability of single measurement by means of a single LaCoste & Romberg gravimeter is to be ±0.02-0.03 mgal. (2) Gravity survey should be made for stations located as distant as possible during a day so far as a LaCoste & Romberg gravimeter is available in gravity survey .
