Xylem pHotoFlex/pHotoFlex Turb - Manual (Page 63)

pHotoFlex / pHotoFlex Turb Operation
63 ba75491d04 07/2006
to mark the optimum position of the cell once it is determined. This
shortens each measurement or calibration procedure with this cell con-
siderably.
The marking can, e. g., be done on a label on the cap of the cell.
4.7.3 Measuring turbidity
Caution
Never pour any liquids directly into the cell shaft. Always use a
cell for measurement. The meter only measures precisely if the
cell is closed with the black light protection cap (WTW cells).
Note
The outside of the cell always has to be clean, dry, and free of finger-
prints and scratches. Clean the cell before starting to measure (see
section 5.2.2). Only hold the cells by the top or by the black light pro-
tection cap.
Measuring
6 Mark the optimum position of the cell.
The cell is prepared for the shortened measuring and calibra-
tion procedures.
1 Press the key (long pressure) repeatedly until the Turbid-
ity measuring mode is selected.
2 Rinse out a clean cell with the sample to be measured:
Pour approximately 10 ml sample into the cell. Close the cell
and rotate it several times before throwing the sample away.
3 Repeat the rinsing procedure twice more.
4 Fill the cell with the sample to be measured (approx. 15 ml).
Close the cell with the black light protection cap.
5 Clean the cell (see section 5.2.2).
6 Insert the cell (see section 4.2).