Ultra High Temperature Instrumentation Amplifier. Midterm Progress Report, September 1976-March 1977

摘要

The design of a downhole instrumentation amplifier to support geothermal well logging without thermal protection at temperatures up to 500 exp 0 C is described. The basic approach is to provide signal conditioning for a transducer, amplify the transducer output and transmit this amplified signal over long electrical cables to the surface for further processing and recording. Ceramic vacuum tubes are used as the active circuit elements to obtain this very high temperature capability. The design phase consists of eight tasks: circuit design, component selection, and room temperature breadboard testing of candidate designs for both the basic amplification and the input stage of the amplifier.