Method and device for testing a still wet coating on running webs

摘要

For testing wet coatings on running webs, a test station with flying light-spot is applied. The light beam generated by a transmitter is guided at an angle to the material web to be tested, which is guided over a roll, and forms an angle between 110 and 155 degrees with the radius of the roll engaging with the scanning line. The reflected light-point of the scanning beam is extended to a light-strip, picked up by the receiver, by the curvature of the roll surface. This means that, during evaluation of the light, relatively large fluctuations between light and dark can be converted into pulses. IMAGE