In Search of More Output: Two Strain Gage Bridge Circuits Revisited.

摘要

The emplacement of large loads via drill pipe is common in Nevada. EG and G Energy Measurements, Inc. is involved in instrumentation. The loading of the drill pipe is of interest and is often measured with strain gages. Sometimes the amount of loading is small relative to the size of the pipe and only produces strain level on the order of 500 to 1000 microstrain. These circumstances have led to implementation of practical methods of measuring these strain levels. The original measurements were made utilizing piezoresistive strain gages with gage factors on the order of 55. Although having large outputs, these gages posed other problems. As a need for more reliable measurements arose, more stable gages were used. These gages have lower output, on the order of 2; therefore, techniques were investigated to gain more output. These techniques used proven circuits and were investigated for the best practical use under our particular circumstances and environments. The results of these investigations will be reported, and conclusions given, in the summary of this presentation. 7 refs.