25 May 2005
TESTING INDUSTRIAL WATER SYSTEM SAMPLES
PURPOSE. Testing of industrial water is performed to determine the
amount of treatment chemicals so dosage levels can be properly regulated. These tests
are a means by which reliable water system operations are ensured, with respect to the
impact of water quality on system equipment and operation. Testing may be conducted
in a permanent field laboratory or at the plant or site location using portable test kits.
USE OF PORTABLE TEST KITS. Portable test kits are primarily for use
at the site location where the sample is taken when an immediate test result is needed.
They can also be used in the permanent field laboratory. Test procedures are provided
with the test kit. For tests that can be conducted either in the field laboratory or with a
portable test kit, use field laboratory test procedures for best results. The water analyst
should periodically check the results of the portable test kit against the field laboratory
test on the same water sample (i.e., perform a check sample analysis). Portable test kits
are available from a number of commercial sources.
LABORATORY PROCEDURES AND TESTING TECHNIQUES. The
achievement of accurate test results is dependent on the use of proper reagents and on
following good, basic laboratory procedures and techniques.
Management of Reagents
Supply. The chemical reagents stored at each field laboratory should be
specific for the tests that are performed. The amount on hand should be adjusted to
ensure the supply is fresh. Reagent containers must be kept tightly closed when not in
use and stored in a cool place. Except for reagents with a specified shorter shelf-life,
liquid reagents should be consumed within one year and dry reagents consumed within
2 years. All reagents should be properly marked with appropriate warning labels, batch
control numbers, and date packaged or discard date clearly marked.
Storage. It is necessary to keep everything in good order at all times.
Have a place for everything and keep everything in its place. Be sure all bottles are
properly labeled and avoid mixing bottles. All bottles should be kept tightly closed. Keep
any reserve stock of solutions and reagents in a cool, dark place.
Apparatus. The apparatus are precision instruments capable of very fine
measurements. Measure carefully, as the results will be "off" if improper sample
amounts are taken, incorrect volumes of solution are added, the burette is not read
correctly, or if the methods prescribed are not performed exactly as written.