抄録
In gravity measurements, a discrepancy among the scale constants of gravimeters used is one of the most essential, important but inevitable problems, especially when a difference of gravity values among the measuring stations is large. Some experimental investigations so far made have been revealed that an amount of the discrepancy among the scale constants for LaCoste & Romberg gravimeters (model G) was to be about ±2×10-4, -remaining the detail unclear. A calibration on the scale constants of 8 LaCoste & Romberg gravimeters (G-29, G-31, G-118, G-124, G-196, G-210, G-305 and G-447) was accordingly carried out, under a harmonious teamwork of the Institutes concerned, during the period of 15 days from October 26 to November 9, 1976, in order not only to make clear the discrepancy among the scale constants of the gravimeters but also to determine the most jreliable gravity values at the measuring stations. The calibration line was newly established between Hokkaido and Okinawa, referring to the International Gravity Standardization Net 1971 (IGSN 71) and the Japan Gravity Standardization Net 1975 (JGSN 75), and itsmaximum gravity difference was of about 1.6 gals. It is ascertained through the present investigation that the correction factor for the scale constants of the 8 LaCoste & Romberg gravimeters given by the manufacturer is ranged to about (28)×10-4 and that the accuracy of the scale constants is to be about(23)×10-5 after making the correction.
