Now available from Bestech Australia , the DEMEC Mechanical Strain Gauge is a single instrument which can take reliable and accurate strain measurements at different points on a structure.
The DEMEC Mechanical Strain Gauge has gauge lengths of 50mm to 2000mm and a discrimination of only two microstrains on the 200mm gauge. This makes the DEMEC strain gauge ideal for strain measurement and crack monitoring on a variety of different types of structures.
The DEMEC Mechanical Strain Gauge consists of an invar main beam with two conical locating points, one fixed and the other pivoting on a special knife edge. The points sit in pre-drilled stainless steel discs, which are attached to the structure with adhesive. The movements of the pivoting point are measured by the strain gauge, which is attached to a base plate on the invar beam. Thermal movement within the instrument is negligible.
200 strains per hour can be measured with accuracy of about ±5 x 10-6 under most laboratory test conditions. Even greater accuracy has been obtained using the gauge in a horizontal position. In development tests of this kind, 90% of measured strains were within ±3 x 10-6 of the mean.
The digital, battery operated, version of the DEMEC strain gauge incorporates a digital indicator with a resolution of 0.001mm, zero set, preset and output for SPC. The indicator can be connected to a data processor for recording and analysis of results. The indicator displays spindle movement digitally by means of a linear encoder and has a response speed of 1000mm per second.
DEMEC strain gauges come complete with an invar reference bar, for control measurements, and a setting out bar for accurate positioning of locating discs.