VORRICHTUNG ZUR UEBERPRUEFUNG VON BESCHICHTETEN UND UNBESCHICHTETEN FOLIEN.

摘要

An optical arrangement for testing the quality of coated or uncoated, pref. sheet foil contains an infrared light source operated by modulated light, a photoreceiver and evaluation electronics. A light source transmits light through the film carrier to a photoreceiver which measures the light. The same point on the carrier is simultaneously illuminated at an angle from the other side. SOme light from the second source is reflected to the photoreceiver. An aperture stop is placed between the carrier and the photoreceiver. The light sources are modulated with different frequencies. The receiver current is converted to a voltage signal which is amplified, separated into two paths by filters and rectified. The signal from the light source can subsequently be delogarithmed.