Abstract: A method for measuring deformations of test samples in testing machines is carried out in a device including a light source, a detector, and signal processing circuitry. The deformations are sensed in that a light beam (2) from the light source (1) is reflected by at least one mirror (6, 6', 6a, 6b, 11a, 11b) arranged at an appropriate location, for example, directly on the test sample (4) so that test sample movements are imparted directly or indirectly to the reflecting mirror or mirrors, whereby the reflected light beam impinges upon a position detector (7) and the position of the impingement or rather its movement is determined and evaluated in an electronic evaluating circuit (8). This movement is a direct measure of the deformation. The device includes components for carrying out these method steps, whereby it is possible to measure static and/or dynamic deformations caused by tensile and compressive forces, as well as deformations resulting from twisting torques and bending moments.

Abstract: In a method and apparatus for measuring deformations of test samples in testing machines, a test sample (4) is clamped into force transmitting units (10, 11). A light source (1) emits a light beam (2) which is reflected from at least one mirror (6, 6') arranged on the force transmitting units (10, 11) to impinge upon a position detector (7) which generates an output signal. The output signal is input to an electronic evaluating circuit (8) to determine the location or rather the location movement of the point of impingement of the light beam on the position detector. Preferably, but not necessarily, each force transmitting unit (10, 11) includes its own mirror (6, 6'), whereby the light beam (2) emitted by the light source (1) is reflected in sequence by the first mirror (6) of the first force transmitting unit (10) onto a second mirror (6') of the second force transmitting unit (11) and then onto the position detector (7).

Abstract: In a test sample clamping apparatus for testing machines, having a clamping head or chuck and a force sensor (2) arranged on the chuck, testing forces are measured with a force sensor and displacements or test sample deformations are measured simultaneously with a light deflection. Thus, rapid test procedures such as fast tensile rupture tests are made possible. The clamping head or chuck includes a base plate (3), one side of which receives or holds clamping elements (15) and the other side of which clamps down the force sensor (2) against a support. A mirror surface (8, 8') is arranged on the base plate (3) or on other appropriate surfaces of the clamping head so as to reflect a ligth beam (10) emitted by a light source (9) onto a position detector (11). In order to measure a deformation caused displacement of the clamping head and correspondingly of the test sample (4), an electronic evaluating circuit (12) evaluates the position dependent output signal of the detector (11).