Basic Photography Course

Courtesy of Beckman Instruments, Inc.

302.259X

Figure 9-3.pH meter.

The ability of a pH meter to determine the pH value

of a solution accurately may be used for the following
purposes:

To verify that chemicals have been properly

mixed

To test prepared chemicals

To assure standardization of the processing

solutions

To determine the exact replenishment rates for

photographic chemical solutions

Tolerances in pH values must be established for

individual labs because of differences in procedures,
types of equipment, impurities in water, and so forth. On
the average, two readings from 10 different batches of
each solution, mixed at different times, must be taken
and recorded to establish these standards. These batches
should be mixed as they would be for regular use but
under very close control to ensure that the solutions are

mixed at the correct temperature, in the proper sequence,
and so forth. This operation helps in determining the
tolerance. This tolerance is the amount of variation of
the pH that still produces high-quality results.

9-5

Courtesy of Kreonite, Inc.

302.20X

Figure 9-4.Agitation mixers.

The discussion of pH meters is intended as an

introduction only. Detailed step-by-step operating
instructions for pH meters are not included in this
chapter. Operating instructions in the form of technical
orders and manufacturer's manuals for specific pH

meters will be available to you in your imaging facility.

MIXERS

In the Navy, we use two methods of mixing

chemicals: hand mixing and machine mixing. Hand
mixing is used when only small quantities of solutions
are needed or when machines are not available. Machine
mixing is necessary to handle the large production
requirements of most Navy imaging facilities.

Agitation Mixers

Proper agitation of the solution during mixing

increases the rate at which the chemicals are dissolved

and prevents undesirable side effects. For proper
agitation, an agitator type of mixer does not cause
excessive amounts of air to enter into the solution
(fig. 9-4). Developers are quickly ruined by oxidation;
a few minutes of improper and violent agitation can

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DOFMaster for Windows On-line Depth of Field Calculator DOFMaster for Mobile Devices On-line Depth of Field Table Hyperfocal Distance Chart Articles FAQ Recommended Books Support Contact Links Home As an Amazon Associate I earn from qualifying purchases.	contents <- previous page next page -> Courtesy of Beckman Instruments, Inc. 302.259X Figure 9-3.pH meter. The ability of a pH meter to determine the pH value of a solution accurately may be used for the following purposes: To verify that chemicals have been properly mixed To test prepared chemicals To assure standardization of the processing solutions To determine the exact replenishment rates for photographic chemical solutions Tolerances in pH values must be established for individual labs because of differences in procedures, types of equipment, impurities in water, and so forth. On the average, two readings from 10 different batches of each solution, mixed at different times, must be taken and recorded to establish these standards. These batches should be mixed as they would be for regular use but under very close control to ensure that the solutions are mixed at the correct temperature, in the proper sequence, and so forth. This operation helps in determining the tolerance. This tolerance is the amount of variation of the pH that still produces high-quality results. 9-5 Courtesy of Kreonite, Inc. 302.20X Figure 9-4.Agitation mixers. The discussion of pH meters is intended as an introduction only. Detailed step-by-step operating instructions for pH meters are not included in this chapter. Operating instructions in the form of technical orders and manufacturer's manuals for specific pH meters will be available to you in your imaging facility. MIXERS In the Navy, we use two methods of mixing chemicals: hand mixing and machine mixing. Hand mixing is used when only small quantities of solutions are needed or when machines are not available. Machine mixing is necessary to handle the large production requirements of most Navy imaging facilities. Agitation Mixers Proper agitation of the solution during mixing increases the rate at which the chemicals are dissolved and prevents undesirable side effects. For proper agitation, an agitator type of mixer does not cause excessive amounts of air to enter into the solution (fig. 9-4). Developers are quickly ruined by oxidation; a few minutes of improper and violent agitation can contents Basic Photography Course <- previous page next page ->	As an Amazon Associate I earn from qualifying purchases.
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