normally used to make five gallons of solution can be dissolved in 12-1/2 quarts of water
and stored in bottles for future use. The rate of replenishment is illustrated in Table 3-2.
NUMBER 14 X 17
FIXING
CLEARING
INCH FILMS
TIME
REPLENISHMENT
TIME (MIN)
FIXED PER
(MIN)
5 GALLONS
Remove 2 qts old solution; replace with
0-50
1-2
5
2 qts replenisher. *
Remove 2 qts old solution; replace with
51-100
1-3
5
2 qts replenisher. *
Remove 2 qts old solution; replace with
101-150
2-3
5
2 qts replenisher. *
Remove 2 qts old solution; replace with
151200
2-3
5
2 qts replenisher. *
Remove 2 qts old solution; replace with
201-225
2-3
7
2 qts replenisher. *
Discard fixer solution; make new
226-250
3-4
8
solution. *
* Replenisher is made by dissolving concentrated fixer in less water than is used in
preparing the fixing bath. RESULT: Replenisher is stronger than the fixing bath. See
manufacturer's instructions for proper dilution.
Table 3-2. Replenishment of x-ray fixing solution (five gallons) in a single tank.
3-30. TWO-TANK FIXING SOLUTION
a. Method. One of the quickest and most economical ways to remove silver
salts from radiographs is the use of the two-tank fixing bath. This bath consists of two
equal sized tanks of fixing solution. The first tank is reserved for clearing the film and
the second tank for hardening of the emulsion. Radiographs are taken from the rinse
bath and placed in the first tank where most of the silver salts removed. When the film
is cleared, it is removed to the second bath where the emulsion is hardened. Because
of this procedure, the second bath has a very low concentration of salts and the
diffusion of the reminder of these salts is exceedingly rapid. Since very few silver salts
are carried over to the washing tank, the washing time can be materially reduced.
b. Replacement. When 180 14 by 17-inch films, or their equivalent, have
passed through the first (number one) tank, discard the solution and move the second
(number two) tank to the number one tank's original position. Make new solution in the
number one tank, which now becomes the number two tank. The original number two
MD0954
3-15