METHOD AND ARRANGEMENT FOR MEASURING BLOWING STRUCTURES OF A PRESTRESSED DISC

摘要

The present invention relates to a method for measuring blowing structures of a prestressed disc (1), wherein at least (a) at least one analysis area (4) of the disc (1) is irradiated with linearly polarized light (5) from a radiation source (2) at an angle of incidence (thetaE) and an image (6) at least of the analysis area (4) is recorded at an observation angle (thetaA) using at least one detector (3), (b) the image (6) is supplied to an evaluation unit (7), and (c) the evaluation unit (7) is used (c1) to read a brightness profile (8) along an analysis line (9) on the image (6), (c2) to determine the local maxima (15) and the local minima (16) of the brightness profile (8), and (c3) to determine an intensity index (IBS) by means of the difference between a brightness average value (Mmax) of the local maxima and a brightness average value (Mmin) of the local minima.