In my recent acquisition of free darkroom material from an uncle, I got in the lot a Cibachrome exposure monitor, but without the instruction manual. He couldn't seem to remember how to use it either. Moreover there's not much info about it I could find on the net or on Ilford's site, so I'd like to ask any color experts here what they can tell me about its usefulness for black and white printing. The thingy is a little black box, with a white console on which there is a on/off switch, a small rectangular area on the left with a little hole that I assume to be the photosensitive cell, and a dial graduated from 0 to 100, labelled "Caliration". Finally on the left of the dial there are two LEDs, labelled "high" and "low".