Fotocount - a Cardboard Edge Counter.

A photomultiplier tube was used with microscope optics to observe the light reflected from a layer, 0.005 inch by 0.060 inch. With a light source at 45 degrees, the device is essentially a microdensitometer. By passing this unit down the side of a pile of cardboard, an output is obtained which is a direct indication of the edge reflectance of each sheet as well as the number of sheets. Noise is reduced and levels are corrected to obtain a digital output which actuates an electronic counter. A modification was also developed to cope with the problem of missing counts caused by sheets obscured by poor jogging.