The SM-5 is composed of two end pieces joined by a tube that protects a length of steel wire. An electromagnet is placed in a protective hou sing located at the center of the tube. The exterior forces applied on the strain gauge modify the tension in the wire and, consequently, the wire’s resonant frequency that is read by the electromagnet. The SM-5 vibrating wire strain gauges are offered in two models: SM-5A and SM-5B, which differ in their mechanical supports. Both models are threaded between two anchor blocks. The SM-5A is held tight by set screws and the SM-5B by hexagonal nuts.
Unless otherwise specified, the gauge tension is factory-adjusted at mid-range and can later be modified by the user according to the anti cipated strain direction. A built-in compressed spring compensates for the wire tension and contributes to making the SM-5 a very compliant gauge. A thermistor incorporated into the gauge supplies information on the effects of temperature on the materials.
The SM-5 strain gauges are designed for quick and easy installation, while offering many possibilities:
Anchor blocks welded to the structure
Anchor blocks welded to a bolt or a short reinforcement bar ready to be bolted, grouted or welded to an expansion shell
A setting tool, holding a dummy gauge, allows both anchor blocks to be positioned accurately.