wtw Turb 550, Руководство по эксплуатации

Страница: 17 / 54

Operation
17
4 Operation
4.1 Instructions for operating
4.1.1 Marking and aligning cells
Even completely clean quality cells exhibit tiny differences in
their light transmittance. Therefore, we recommend marking
each cell (both measuring cells as well as cells with the cal-
ibration standard). Consequently, each cell can always be
inserted in the correct position and you can achieve precise
measuring results.
Cleaning the cell The cell must be absolutely clean (see 5.2.2 C
LEANING THE
CELLS
).
Marking the cell This is how to mark a cell (empty or full):
Note
Always use the cell and the light protection cap together;
only in this way is the cell marked.
1 The cell must be closed with the black light protection
cap. Make sure that the outside of the cell is clean,
dry and free of fingerprints
2 Insert the cell in the cell shaft of the turbidity measur-
ing instrument
3 Slowly rotate the cell through one complete rotation
(by 360°)
4 Watch the display of the turbidity measuring instru-
ment while you rotate the cell. Leave the cell in the
position that gives the lowest display.
5 Attach a marker ring to the black light protection cap
of the cell. The arrow on the marker ring must point to
the marker pin on the casing of the cell shaft.
6 Leave the marker ring on the light protection cap of
the cell. This cell is now permanently marked.