HF scientific MicroTPI Field Portable Turbidimeter (Old) - Manual (Page 15)

6.0 Routine Maintenance
If you do not plan on leaving the instrument in the supplied carrying case, when not in
use, ensure that the instrument has been turned off and that a clean sample cuvette fitted
with a black cap has been placed in the sample well. This will ensure that a minimal
amount of dust and/or debris will be able to settle on the optics of the instrument.
6.1 Cuvette Cleaning and Care
Proper measurement of the turbidity of a sample requires the use of a cuvette that is free
of marks, smudges, scratches and any bacterial growth. Cleaning the cuvette is
accomplished by washing the interior and exterior of the cuvette in a detergent solution.
Once cleaned, the cuvette should be rinsed thoroughly 8 to 10 times with clean distilled
water to eliminate the possibility of detergent buildup and streaking. Cleaned and dried
cuvettes should be stored with the black caps on. The cuvettes can be stored in a cuvette
rack (see accessories and replacement parts list). During normal operation you may use
any typical glass cleaner along with a lint free cloth or tissue (Kimwipes®), to clean the
outside of the cuvettes.
Condensation may appear on the cuvette when your sample is very cold and the relative
humidity is high. When this happens, the turbidity that you read may be higher than the
actual turbidity due to the light scattered by the condensate on the cuvette. If you find
yourself in this circumstance you can alleviate the problem by either coating the cuvette
with an anti-fogging agent, or by running warm water over the cuvette for a short period
of time to warm the sample prior to measurement.
Ref. 22666 (12/04)
Rev. 1.4
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