3-59. SOLUTION LEVEL
For efficient time-temperature processing, the level of the developer solution in
the tank should be kept at a constant point. Absorption and carryover to the rinse bath
gradually reduce the level of the developer solution. When radiographs are removed
from the developer, the amount of solution carried away by the film depletes the
volume. This causes the surface level to drop below the top level of the films contained
in the processing hangers. (At least three ounces of solution, for example, are
contained in the emulsion of a developed 14 by 17-inch film.) Before the level reaches
this point, however, new solution must be added to maintain the original level. If
solution is not added, the upper portion of the film is not immersed and thus is not
developed. The addition of the developer also restored by the frequent addition of fresh
developer or replenisher, depends upon the system being used. Water should never be
used to maintain the solution level, since this would dilute the solution. Replenisher
should never be added when films are in solution because over development would
occur on those areas of film coming in contact with this "strong" solution.
3-60. SECONARY CHARACTERISTICS OF DEVELOPER SOLUTION
Secondary characteristics of developer solutions frequently cause difficulties that
may be considered in two ways--those that affect the chemical balance and composition
of the solution and the effects of those chemical conditions on the radiograph.
a. Effects on Developer Solution. Various conditions to which developer
solution may be subjected can cause a variety of problems.
(1) Low activity. Low activity may be the result of incorrect mixing, an error
in dilution, or low temperature. An unusual drop in activity may be attributed to the
addition of water instead of fresh developer to raise the solution level, contamination
from fixing solution or acid rinse bath, or inadequate replenishment. The remedy is
adherence to a correct processing routine.
(2) High activity. High activity is seldom encountered, but it may occur
because of high temperature or the addition of more replenisher than is necessary. The
remedy is to follow time-temperature processing and a correct replenishment routine.
(3) Crystallization of chemicals. Crystallization of chemicals is caused by
insufficient dilution when mixing or by storing the solution at low temperatures. Proper
dilution should be maintained when mixing the solution. If crystallization occurs
because of low temperatures, warming the solution to 125F may redissolve the