TESTER FOR IDENTIFYING ADAPTABILITY OF CERTIFICATE

摘要

The device has a light source and a reference grid reciving the light from the source. A holder for the paper is placed between the light source (16) and the reference grid (18). The paper (14) carries out a relative movement w.r.t. the grid (18) so that the light passing through the grid (18) is chopped. A scanning device (22) is connected to the reference grid for the transmitted light reception and for its testing for the chopping frequency and for the paper optical density. It detects the paper genuiness.