Compensating for evaporation from a photographic processing vessel

摘要

A system for processing photographic material has a series of processing vessels containing different water-based processing baths. A reference vessel is mounted on one of the processing vessels and serves to compensate for the evaporation of water from the processing vessels. To this end, the reference vessel accommodates a body of water as well as a float switch having an upper contact and a lower contact. The reference vessel and processing vessels are open at the top and a feeding arrangement is provided to admit water into the respective vessels through their open tops. The feeding arrangement includes one or more pumps connected to a control unit which is further connected to the float switch. When evaporation causes the water in the reference vessel to fall to the level of the lower contact of the float switch, the control unit activates the pump or pumps to replace the water lost from each of the vessels by evaporation.