densitometer

densitometer (In French densitomètre) measuring device with which the optical density or color density (light obscuration) is determined as a indirect measure for the layer thickness of the printing ink. The thickness measurement requires a polarization filter which compensates for the differences between wet and dry ink layers. Compared to obsolete devices with the optical filters R, G, B and Vis (for measuring of black ink), densitometers today work with a spectral scanning head and calculate the density values virtually. Measuring filter characteristics and device calibration (with reference to paper white or absolute white) differ in geographical markets: Europe: “Status E” (ISO/ANSI E, DIN 16536, broadband with respect to paper white, higher yellow values than Status T), America: “Status T” (ISO/ANSI T, broadband with respect to absolute white), “Status I” (ISO/ANSI I, DIN 16536 NB, narrow band with respect to paper white); furthermore “Status M” (broadband measurement of transmitted light), “Status A” (only photographic industry, broadband reflected and transmitted light measurement).