wtw Turb 430IR Mode D'emploi Abrégé page 10

Operation
Marking a cell
Measuring turbidity
10
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.
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.
The outside of the cell always has to be clean, dry, and free of
fingerprints and scratches. Clean the cell before starting to measure.
Only hold the cells by the top or by the black light protection cap.
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.
5 Insert the cell.
6 Align the cell:
! Marked cell
– Align the marking on the cell cap with the marking on the
cell shaft.
– Press and for a short time hold the <START/ENTER>
key until the measured value is displayed.
! Unmarked cell (see page 9)
– Press and hold the <START/ENTER> key.
– Slowly and in small steps rotate the cell by one complete
rotation (by 360 °). After each step wait for a short time
until the displayed measure value is stable.
– Turn the cell back to the position with the lowest
measured value.
7 Release the <START/ENTER> key.
Measurement starts. The measured value is displayed.
Turb 430 IR
ba75506e01 04/2005