a. Development. Development is by time and temperature in tank one,
according to table 4-2. After development, the film is removed quickly and drained to
waste for 15 seconds (do not drain into the developer tank). The waste can be a trough
in the back of the tanks leading to a drainage pit outside the processing room structure.
b. Rinsing. The film is next placed in tank two containing an acid rinse bath
(stop bath) made by mixing 2-1/2 quarts of 28-percent acetic acid with five gallons of
water. Exhaustion of this bath occurs when 200 14- by 17-inch films, or their equivalent,
have been passed through the solution. If an acid rinse bath is not available, a fresh
water rinse bath can be used, but it must be changed after 40 14- by 17-inch films have
been rinsed. The film should be rinsed in tank two for one minute with active agitation
or for two minutes without active agitation. After rinsing, it is removed and drained to
tank two for 15 seconds and then immersed in tank three for fixing.
c. Fixing. Tanks three and four are used for fixing solution. The fixing solution
should be mixed using a sodium thiosulfate formula. The film remains in tank three
from one to two minutes until clear. It is then removed and drained to tank three for 15
seconds before being placed in tank four, where it remains two minutes for hardening.
Be sure that the fixing solution from tank three does not drain into tank three. When 80
14- by 17-inch films have been passed through tank three, it is replaced with new
solution and tank four is moved into number three position. The new solution in tank
three then assumes the number four position.
(1) Washing is a precise operation in this procedure and all the rules must
be observed if a radiograph of quality and permanence is to result. For this operation,
freely circulating water is not used. When the film is removed from tank four, it is
drained for 15 seconds to tank four, or to waste, and then immersed in tank five where it
is agitated for one minute (leave it in tank five for two minutes if it is not agitated). It is
then removed and drained for 15 seconds to tank five, or to waste, before being placed
in tank six. After agitation for one minute in this tank, it is removed to drain into tank 6,
or to waste, for 15 seconds. The film is then immersed in tank seven for one minute
while being agitated (or for two minutes if not agitated) and then removed to drain into
tank seven, or to waste, for 15 seconds. Tank seven also contains a wetting agent
(Table 4-2). In the process of transferring films between tanks five, six, and seven, if
the films are drained to the waste, be sure that each water level is maintained by the
frequent addition of fresh water to compensate for the water loss. The film may then be
placed in the dryer or viewed by the radiologist or surgeon.