The DEMEC portable strain gauges available from Bestech Australia are designed for making strain measurements reliably and precisely at different points on a structure using a single instrument.
Offering a discrimination of 2 micro strain with the 200mm gauge, and gauge lengths of 50mm to 2000mm, the DEMEC portable crack strain gauges are ideal for use on many types of structures for strain measurement and crack propagation studies.
Typical applications of DEMEC portable strain gauges include civil engineering structure tests on bridges, road surfaces, retaining walls, dam walls, smoke stacks and chimneys as well as airport tarmacs.
Functioning of the DEMEC portable strain gauges
The DEMEC crack gauge comprises of an invar main beam with two conical locating points, one of which is fixed while the other point pivots on a knife edge.
To measure the strain or crack propagation, the crack gauge is manually held over two stainless steel discs adhered to the structure under test. Typically, a disc is adhered on the material surface on either side of a crack in the surface.
The conical locating points in the gauge are seated into a precision drilled bore in the centre of each locating disc. The resultant displacement of the pivoting point is then indicated by the gauge. Thermal expansion and contraction within the instrument is inherently insignificant by design.
DEMEC portable strain gauges are available in digital and mechanical versions.
Key features of DEMEC portable strain gauges:
- Digital strain gauges incorporate a battery operated digital indicator with a resolution of 0.001mm
- Digital indicator has a ZERO SET button and a PRESET button
- Digital signal for connection to a data processor for recording and analysis of the results is also included
- Mechanical strain gauges indicate strain or displacement via a high precision dial gauge
- Supplied in a carry case complete with an invar reference bar for controlled measurements
- Set of locating discs and an instruction manual are also included