6.
Replenishment. The developer and fixer replenishment systems pump developer and fixer to the
processing tanks from the storage tanks.
a. The solution is filtered before being introduced into the existing chemistry in the processing tanks.
This is necessary because the chemistry in the storage tanks is undiluted and if added directly to the solution tank
would cause uneven development and fixation.
b. The replenisher pumps can be operated continuously or automatically and are usually controlled by
micro-switches located at the food entrance of the processor. They sense the materials as they enter the machine
and activate solenoids adding the right amount of replenisher.
c. The purpose of replenishment is to maintain the activity of the solution at a constant level
throughout processing operations.
7.
Water Circulation. The water circulation system on a processor operates from regulated pressure through
a water mixing valve and a flow meter. It provides fresh water to the wash and spray tanks. Water temperature
is regulated by a thermostatically controlled valve in the mixing valve.
8.
Drying Systems. The drying of paper is a simple task for a print processor. The papers being used most
often today are resin-coated (RC) and absorb less chemistry than a paper that is not an RC-type paper. Less
chemistry is absorbed allowing for easier removal of the various solutions and a more rapid drying pace.
a. Processors dry paper by two methods, forced-air, heat, or both. Larger processors use the forced-air
method and have a housing at the end of the machine where the paper enters to have warm air blown over it to
be dried. Smaller machines use a combination of heat and forced-air to dry paper.
b. It is important to know the drying temperature for your particular type of paper. All photographic
papers are not made to be dried at the same temperature. Some problems that can occur if the temperature is
incorrect are water spots if the temperature is too low and excessive curling of the paper if the temperature is too
high.
c. The exact limits are dictated by the material being dried, and the type of dryer being used.
9.
Safety. There are three basic areas of safety: chemical, electrical, and mechanical.
When you are
working with a print processor, you will be confronted by all three areas simultaneously.
a. Chemical. When working with photographic solutions you should always consider that they will be
harmful if mishandled. Never try to determine the contents of a container by sniffing. If in doubt discard it
and obtain a bottle that is properly labeled. When mixing chemicals always wear protective clothing to include
eyewear and rubber gloves and always follow the manufacturer's instructions. Most important of all, never add
water to a acid or alkali. Rememeber AAA - Always Add Acid or Alkali to water.
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