Abstract: A process for monitoring the electrolyte circulation in an electrolysis cell, in which an electrolyte flow generated by a circulation pump is generated between the electrodes of the electrolysis cell and the electrolysis is performed by a constant electrolysis current or electrode potential.

Abstract: Interface for a silver recovery unit (11) for indicating the operating condition of at least one pump (9a, 9b). A sensor (10) for detection of the operating condition of the pump (9a, 9b) is installed outside the at least one pump (9a, 9b) such that during installation an intervention in the electronic unit (24) of the pump (9a, 9b) or in the pump (9a, 9b) itself is avoidable. The output signal of the sensor (10) is passed to a series-connected electronic circuit (400) that comprises a series connection of an amplifying means (40), a first filtering means (41), a rectifying means (42), a second filtering means (43) and a comparator (44).

Abstract: The apparatus allows at least two film processor fixing solution tanks for black and white films with silver-based coating to be connected to a silver recovery unit. To that end, an intermediate storage tank is connected between the fixing solution tanks and the silver recovery unit. The intermediate storage tank is divided by an impervious internal partition into two chambers of equal size. The pipes connect the overflows of the fixing solution tanks to the inlets of the first chamber. Another pipe connects the outlet to the silver recovery unit. The return pipes connect the outlets of the second chamber to the inlets of the fixing solution tanks. A pipe connects the silver recovery unit to the inlet of the second chamber.

Abstract: The invention relates to a method and apparatus for controlling electrolytic silver recovery for two film processing machines which enables the fixing baths to be connected with a silver recovery unit according to their level of silver concentration. According to the invention, the silver concentration in a fixing bath having a liquid connection with the silver recovery unit and in an unconnected fixing bath is continually calculated by electronic means and a control signal is generated when the difference in silver concentration between the connected and the unconnected fixing baths reaches a pre-definable level, said control signal causing actuators to connect the silver recovery unit with the fixing bath having the higher concentration of silver. When the silver concentration reaches a pre-definable level an electrolysing current in the silver recovery unit is switched on and remains switched on until the silver concentration falls below the pre-defined level.

Abstract: A method for the electrolytic recovery of silver is disclosed. The silver is recovered from two film processing machines. Each machine has a fixing bath. Silver concentration is determined in each bath by an electrolysis cell of a silver recovery unit The silver concentration is used for connecting the fixing baths.

Abstract: A method and apparatus for controlling an electrolytic silver recovery system for a photographic processor, the control being effected in response to the surface area of the photosensitive material moved through the processing solutions. The apparatus determines the amount of silver deposited in the fixing bath of the processor from the width, length and density of the photosensitive material and used as an electrical signal for controlling the electrolytic current of the silver recovery system.

Abstract: Process and device for the feeding of fluid additives and, in particular, of replenishers to a photographic processing fluid. Fluid additives are supplied to the processing fluid contained in a photographic processing tank by a feeding duct. The feeding duct is filled with processing fluid before different fluid additives are introduced into the feeding duct. The volume of the fluid additive supplied is measured by a flow meter which is arranged in an area of the feeding duct which during the measuring operation carries only processing fluid and not the fluid additive being fed into the feeding duct.