TJ-1型体积式钻孔应变仪已试用十余年,取得一定的实效。根据中国地震局,《九五规划》要求,1996～1998年进行实用化研究,其中也包括电子线路部分也需作多处相应的改进。已研制成功的TJ-2型小型化体应变仪,它不仅对井下仪器作了小型化与系列化的改造,在电子线路部分亦相应作了改进。本文重点介绍了在讯号传送方面的研制情况,其量程(优于6×10~(-6)应变)范围、噪声水平(优于6×10~(-9)应变)等主要技术指标都有明显提高,且电压输出格式能符合数字化台网建设的要求。二、压力传感器的选型传感器(即传感单元)在体应变仪的发展进程中,已经从“波纹管+差动变压器”(即TJ-1型)发展为差压式液压传感器(即TJ-1A型),而后者又由交流型压力传感器(即 TJ-1 volumetric borehole strain gauge has been tried for more than ten years and achieved some results. According to the requirements of China Earthquake Administration and the Ninth Five-Year Plan, from 1996 to 1998, practical researches were conducted, including the corresponding improvement of the electronic circuit parts. TJ-2 miniature body strain gauge has been successfully developed. It not only miniaturizes and serializes the downhole equipment, but also improves the electronic circuit part accordingly. This article focuses on the development of the signal transmission, the range (better than 6 × 10 -6 strain) range, the noise level (better than 6 × 10 -9 strain) and other major technical indicators have Significantly improved, and the voltage output format can meet the requirements of digital network construction. Second, the pressure sensor selection Sensor (ie, sensing unit) in the development of body strain gauge, has been developed from the “bellows + differential transformer” (ie TJ-1 type) to differential pressure hydraulic sensor (ie TJ -1A), while the latter by the exchange-type pressure sensor (ie