Abstract: Mounted within the measuring section (10) formed by two clamping devices (2, 4) are measuring rollers (8, 9) which deflect the test material (10). The deflection results in a force couple (P, P′) and a resultant force (R). The resultant force (R) is transferred into a load cell (3) via a link (6). This arrangement enables the clamping devices (2, 4) and the load cell (3) to be mounted separately. The measuring rollers (8, 9) are equipped with incremental transducers (19, 20) by means of which the clamp slippage (&Dgr;1) creeping out of the clamping faces of the clamping devices (2, 4) and the extension of the test material sections (10′, 10″) are measured.

Abstract: An apparatus for inserting a thread between the testing clamps of a tensile strength testing apparatus has an insertion clamp which can travel vertically on a slide movable on a vertical rail which is also movable horizontally, whereby movement of the insertion clamp in orthogonal directions is possible. An automatic control mechanism is operable to command a drive arrangement for the insertion clamp to move the clamp along any desirable path which carries the thread to the required position in the testing apparatus.