wtw Turb 430 IR/T, Operating Manual

Page: 34 / 72

Operation Turb 430 IR/T
34 ba75507e04 06/2009
Note
To keep the drift as low as possible, the time for aligning the cell while
pressing and holding the
<START/ENTER> key is limited to 30
seconds. After this time, the meter starts measuring automatically.
Marking a cell To be able to quickly bring a cell into the optimum position, it is helpful
to mark the optimum position of the cell once it is determined. This
shortens each measurement or calibration procedure with this cell
considerably.
The marking can, e. g., be done on a label on the cap of the cell.
4.5.3 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
fingerprints and scratches. Clean the cells before starting to measure
(see section 5.2.2). Only hold the cells by the top or by the black light
protection cap.
Measuring
4 Release the <START/ENTER> key.
Measurement starts. The measured value is displayed.
5 Mark the optimum position of the cell.
The cell is prepared for the shortened measuring and
calibration procedures.
1 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.
2 Repeat the rinsing procedure twice more.
3 Fill the cell with the sample to be measured (approx. 15 ml).
Close the cell with the black light protection cap.
4 Clean the cell (see section 5.2.2).
5 Insert the cell (see section 4.2).