| abstract |
To determine the color values of reflective and transparent thin-film layers applied to substrates, a method for determining the reflectance curve is used, in which instabilities caused by the apparatus and which interfere with the color value measurement are corrected by normalizing the measured radiation functions to the current measurement light spectrum and by taking account of extraneous light influences superimposed on the measurement spectra. The measuring device comprises a light source (4,6a) illuminating the substrate surface to be examined, an optical device in a first beam path (20,9,8b, 10b) with which the light reflected or transmitted by the substrate onto the entrance slit (16) light-dispersive and light-detecting device (14) can be steered, and means with which the characteristic emission spectrum of the direct light component emitted by the light source can be fed to the light-dispersive device (14) for the purpose of spectral analysis. The first beam path (20, 9, 8b, 10b) and at least one second beam path (13, 8a, 10a) can be mutually separated from each other in a light-tight manner using a diaphragm device (11b, 11a).n n n The light source (6a) consists of a photometer ball (6a) in which a lamp (4) is arranged. A permanent light source, in particular a halogen light lamp, is provided as the lamp (4). Long-term Instabilities are essentially corrected with a white standard and short-term instabilities, taking into account the characteristic emission spectrum of the lamp (4) used. |