Understanding Neutron Radiography Reading V-Kodak Part 2 of 3

During use, the fixer solution accumulates soluble silver salts which gradually
inhibit its ability to dissolve the unexposed silver halide from the emulsion. In
addition, the fixer solution becomes diluted by rinse water or stop bath carried
over by the film. As a result, the rate of fixing decreases, and the hardening
action is impaired. The dilution can be reduced by thorough draining of films
before immersion in the fixer and, if desired, the fixing ability can be restored
by replenishment of the fixer solution. The usefulness of a fixer solution is
ended when it has lost its acidity or when clearing requires an unusually long
interval. The use of an exhausted solution should always be avoided because
abnormal swelling of the emulsion often results from deficient hardening and
drying is unduly prolonged; at high temperatures reticulation 网 状 组 织 or
sloughing 脱 落 away of the emulsion may take place. In addition,
neutralization of the acid in the fixer solution frequently causes colored stains
to appear on the processed radiographs.
Charlie Chong/ Fion Zhang
Radiography in Modern Industry. Rochester, NY: Eastman Kodak Co. 1980