The strain gauge (DMS) rests on the principle, that a part is mechanically deformed and this deformation is relayed by a meander-formed wire (=DMS). Through the straining of the wire, a varying electric resistance occurs, which consequently represents the measurement of the materials mechanical deformation.
This procedure is frequently used for tension- and pressure measurements and appears to be simple in its application to determine a torque value, the DMS-gauge is generally arranged 45-degrees to the torsion axis and the electrical resistance is obtained by using several gauges.
The usable linear area between the torque and the resistance change is not as large as with the Piezo transducer. They are made to correspond with the respective torque-ranges of our screwdrivers. Because of the rather large spread and many different standard available components, this is a relative low-cost solution.
Our products are located in PDF Product Catalog D 3020.