Application of proving-ring technology to measure thermally induced displacements in large boreholes in rock

A strain-gauged proving-ring transducer was designed and deployed to measure small diametral displacements in 0.61-m diameter boreholes in rock. The rock surrounding the boreholes was previously heated by storage of spent nuclear fuel assemblies and measurements during post-retrieval cooling of the rock were made. To accomplish this, a transducer was designed to measure displacements in the range of 10 to 100 {mu}m, to function in a time-varying temperature regime of 30{sup 0} to 60{sup 0}C at a relative humidity of 100%, to be of low stiffness, and to be easily and quickly installed. 7 references, 6 figures, 1 table