wtw Turb 555, Operating Manual

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Turb 555 / Turb 555 IR Operation
17 ba41113e07 04/2009
4 Operation
4.1 Instructions for operating
4.1.1 Marking and aligning cuvettes
Even completely clean quality cuvettes exhibit tiny direction-
al differences in their light transmittance. Therefore, each
cuvette should be marked - both the measuring cuvettes as
well as the cuvettes with the calibration standards (refer to
section 2130 of the "Standard Methods for the Examination
of Water and Wastewater", 19th edition). Consequently,
each cuvette can always be inserted in the correct position
and you can achieve precise and reproducible measuring
results.
Cleaning the cuvette The cuvette must be absolutely clean (see section
5.2.2 C
LEANING THE CUVETTES
).
Marking the cuvette This is how to mark a cuvette (empty or full):
1 The cuvette must be closed with the black light pro-
tection cap. Make sure that the outside of the cuvette
is clean, dry, and free of fingerprints.
2 Insert the cuvette in the cuvette shaft of the turbidi-
meter.
3 Slowly rotate the cuvette through one complete rota-
tion (by 360°).
4 Watch the display of the turbidimeter while you rotate
the cuvette. Leave the cuvette in the position that
gives the lowest display.
5 Attach a marker ring to the black light protection cap
of the cuvette. The arrow on the marker ring must
point to the marker pin on the casing of the cuvette
shaft.
6 Leave the marker ring on the light protection cap of
the cuvette. This cuvette is now permanently marked.