PROCEDURE FOR ANALYSING THE VISIBLE CLOUDING OF SAFETY PAPER AND DEVICE FOR THE PERFORMANCE THEREOF

摘要

The paper to be analysed is made to pass through an acquisition unit (2), on a platform (5) thereof, from an entrance (6) to an exit (7), conveniently directed by a guide (8) and drawn by a traction motor (10) with the collaboration of photocells (9-9') which detect the entrance and the exit of the paper, specifically making it pass through an emitter-receiver combination (12), in which the light beam is modulated by the nonuniformity in the thickness of the paper, variations in the modulation of light which are converted into voltage variations to be applied to a processing and display unit in which participates a data acquisition card and a computer, where the signal is converted into digital form and wherein the processing thereof is carried out to extract the parameters which will characterise the cloudiness of the paper sample. IMAGE