差動トランス型水管傾斜計の試作

Abstract

For the continuous observation of the secular variation of ground tilt, a water tube tiltmeterhas been used at each crustal movement observatory in Japan. This instrument is very reliable, but there arc many difficulties to record the level variation of water surface. Therefore, the methodof visual reading with micrometer has been adopted traditionally.To realize an automatically recording system, a water tube tiltmcter of differential transformertype was designed and set at the adit of the Hokuriku microearthquake observatory. In thispaper, the observing system of this instrument is mainly described.