e. In the preceding diagrammatic examples, the amount of silver deposited by
development depended upon length of exposure of the silver bromide crystals to x-rays,
the length of time of development, and the temperature of the developing solution. As
the development time and/or temperature of the developer increases, the amount of
silver deposited increases, and vice versa. Radiographic density and other film
characteristics are influenced by the time of development and the temperature of the
solution, adequate density control may be obtained by standardization. Once this is
achieved, radiographic density as influenced by development may be considered a
constant.
3-41. STANDARDIZATION OF PROCESSING PROCEDURES
Uniform radiographic quality can be achieved only through control and
standardization of processing procedures. X-ray film is manufactured to produce a
consistently uniform degree of density and contrast when correctly exposed and
processed according to standard and accepted procedures. Familiarity with the
performance of a particular film is necessary for any measure of standardized
processing. Since the characteristics of density and contrast provided by a particular
film and its developer are inherent, they may be considered constant. The sequence of
chemical activities in processing is smooth and organized and produces a desirable
image when standardized procedures are followed.
3-42. VALUE OF STANDARDIZED PROCESSING PROCEDURES
a. There are several ways that a film may be developed, but the standard time-
temperature method is almost universally used. This method is virtually foolproof and
provides an excellent means for checking x-ray exposures. The quality of a radiograph
depends upon full development of the x-ray film within a limited temperature range.
Variations from the optimum must be carefully compensated to maintain quality. Once
standardized, processing rules are established and followed, overall changes in density
and contrast can be attributed to exposure factors. Standardized processing of the film
can then become a constant as long as a reasonable measure of discipline is exercised
in the processing room.
b. Photographic research has so standardized processing procedures that
operations in connection therewith have been reduced to noting the time-temperature
and setting an interval timer according to a simple time-temperature chart. This
procedure, however, is based upon the accumulated knowledge of the many chemical
and physical complexities relating to the exposure and the development response of the
film. Despite the simplicity of a standard processing procedure, it will not work
satisfactorily, if solutions are improperly mixed, contain poor quality chemicals, or not
used in accordance with the manufacturer's instructions.
MD0954
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