wtw Turb 350 IR, Руководство по эксплуатации, Страница: 18 / 42

Operation
60
4.2 Measuring turbidity
Warning
Never pour liquid directly into the cuvette shaft. Always use
a cuvette for the measurement. The measuring instrument
only measures precisely when the cuvette is closed with the
black light protective cap (WTW cuvettes).
Note
The outside of the cuvette always has to be clean, dry, and
free of fingerprints. Clean the cuvette before starting to mea-
sure (see section 5.2.2 C
LEANING THE CUVETTES
). Only hold
the cuvettes by the top or by the black light protection cap.
Measuring This is how to measure the turbidity of a sample using the
Turb 350 IR:
1 Switch on the turbidity measuring instrument by
pressing the key. Let the turbidity measuring in-
strument warm up for at least 75 s. During this time,
continue with the steps 2 to 5.
2 Rinse out a clean cuvette with the sample to be mea-
sured:
Pour approximately 10 ml sample into the cuvette.
Close the cuvette and rotate it several times before
throwing the sample away.
3 Repeat the rinsing procedure twice more.
4 Fill the cuvette with the sample to be measured (ap-
prox. 15 ml). Close the cuvette with the black light
protection cap.
5 Make sure that the outside of the cuvette is clean,
dry, and free of fingerprints.
6 Insert the cuvette in the cuvette shaft so that it clicks
into place.
7 Align the cuvette (see section 4.1.1 M
ARKING AND ALI
-
GNING CUVETTES
).