The mechanical strain gauge consists of a highly repeatable measuring tool that is also removable. During deformability tests by using flat jacks, the mechanical strain gauge (usually with a measurement base of 250 mm) is used for the detection of convergence measures across the cutting in which the jacks are introduced. It consists of a stainless steel bar with two heads with cone points mounted at each end. One of the heads is fixed, while the other is free to flow, minimizing backlash thanks to high-precision mechanics. The cone points of the instrument should be placed in the small holes of special stainless steel pillars that should be applied, using the template provided, to the structure that needs to be checked with the adhesive supplied.
The equipment consists of:
• a full digital mechanical strain gauge
• a steel calibration bar with a low expansion coefficient
• a space template for placement of disks
• 50 reference disks
• adhesive for attaching disks
All parts are contained in a practical, robust, watertight carrying case.