METHOD OF ASSESSING THE ACTIVITY OF A PHOTOGRAPHIC DEVELOPER AND APPARATUS THEREFOR

摘要

A latent photographic image of a sensitometric wedge (1) is developed and density curve data relating to the resulting wedge print is determined using a photoelectric transmission densitometer. This is compared with results from a sample of developer, taken to be the norm. The densitometer is used to determine a notional density range in terms of the difference between the dark current of the photodetector, and the photodetector output current when it is irradiated via the transparent support having zero image density. A further comparison is made between points along the wedge.