Material testing instrument, in particular metal-sheet testing instrument

摘要

The invention relates to a manually operated material testing instrument, in particular a metal-sheet testing instrument, for testing uncoated and coated thin metal sheets by pressing a spherical die into the metal-sheet specimen. It has devices for observing the progress of the test and for reading off the test values. The object of the invention is to construct the instrument so that the region to be observed during the indentation test and the scale for measuring the amount of indentation are enlarged without distortion by means of convex lenses and are illuminated by means of fibre optics, according to the invention via the individual strands of an optical waveguide. The invention, which is shown in the figure, may be applied to material testing instruments in which local deformation processes which are to be precisely observed and measured occur in thin metal sheets. <IMAGE>