specks to acquire atomic (photolytic) silver ions form the disintegrating silver bromide
crystals are exhausted. The bromine ions are freed from the emulsion and react with
the potassium ions form other completion of development; the exposed silver bromide
crystals have been reduced to bock metallic silver, which constitutes the image. The
unexposed and undeveloped silver bromide crystals remain largely unaffected, but are
removed by a later treatment (fixing).
3-22. DEVELOPMENT REPLENISHER SYSTEM
The replenisher system is an efficient method of development. In the replenisher
system, a solution of greater activity than the original is used to keep the activity of the
solution constant. This makes it possible to keep development times constant. The
companion replenisher for the developer being used should be the one utilized.
Developer from one manufacturer and replenisher from another should not be used,
since the formulas may not be compatible.
3-23. DEVELOPMENT REPLENISHER SYSTEM OPERATION
a. When using the replenisher system, film should be removed from the
developer quickly and the excess solution should not be drained back into the developer
tank, but rather into the waste outlet. Normally, this procedure will remove about the
proper amount of solution for efficient use of this system. Approximately one gallon of
replenisher should be added for every forty 14 x 17-inch films or the equivalent. If
sufficient solution has not been drained to waste by the films, it may be necessary to dip
a measured quantity of developer from the tank and to add a comparable amount of
replenisher to maintain normal developing activity. However, by the frequent addition of
small quantities of replenisher solution, the proper level of the developer and the activity
of the solution can be easily maintained. This procedure relieves the specialist of the
responsibility for computing the actual quantities needed for replacement; however, a
record of the volume of replenisher used must be maintained.
b. It is important that you never add replenisher solution to the developer while
films are developing. This may ruin the films with streaks of very high density.
c. A rough estimate of the number of films that can be developed in a properly
replenished developer has been determined to be 125 14 by 17-inch films per gallon of
solution or 625 films in a five-gallon tank. Beyond this, it is not practicable to replenish.
The solution should be discarded and a fresh batch mixed. Another way to compute the
life of replenished solutions is to discard them after the replenisher used equals three or
four times the quantity of the developer. By carefully reading the manufacturer's
instructions for replenishment on the label of the container, the specialist can determine
the correct amount of replenisher. It is also recommended that the solution be
discarded after three months, regardless of use, because oxidation of the reducing
agents results in a decline of developer efficiency. This procedure must be followed
even though the total amount of replenisher has not been used during the period.