DEVELOPMENT OF SS-Y SHORT-BASED EXTENSOMETER AND ITS CALIBRATOR
Lü Chongwu, Sun Yaqiang, Du Weimin, Li Jiaming, Zhan Biyan, Gao Ping, Luo Yu, Zhou Zhongyi and Lü Fuqi 1)Institute of Seismology, CSB, Wuhan 430071 2)Seismological Bureau of Shandong Province, Jinan 250014
In this paper, the design procedure, composition and principle of short datumline extensometer on SS Y model and the test results of the extensometor are described. Because of using the transformer with high sensitivity and the calibrator with super microdetector and taking super Nb Invar rod as datum line, the extensometer have high accuracy and stability under the shortened datum line. It can record clearly earth tide with the accuracy of better than 10 -9 when the NS component of datum line is 6 m and the EW component is 10 m. The problems of quart tube rending and mercury leaking are thoroughly overcome.