“Almost 50 years and not a bit tired”- this was the status of to our “longest serving employee,” our old and experienced (formerly analog, later laboriously digitised) tensile tester. But now the tester had to retreat from daily work.
Although the main testing equipment for quality assurance – from the devices of the sand laboratories on the hardness test devices to pendulum impact tester and tensile testing machine – is “unbreakable”, an exchange sometimes is necessary. The base elements are dimensioned for eternity, but wear on bearings, restoring elements etc. and especially the digitisation of the measurement signals and their integration into a “quality assurance 4.0” requires an equipment replacement.
Since March 2016 a universal testing machine of the German manufacturer Zwick / Roell is working in the test room. Tensile testing is performed on a fixed and second moving crosshead. This moves at a defined rate (depending on inspection specification) in a direction to tear the test-piece, which is held by the sample holder between the trusses. The deformation of the sample on the distance, where the crosshead was moved, and its elongation (by using a strain sensor (Extensometer)) and the force required to enlarge and at least to destroy the sample are recorded by a load cell. Using the sample dimensions and the used mechanical loads stresses and strains are calculated.