wtw pHotoFlex, Operating Manual

Page: 67 / 111

pHotoFlex / pHotoFlex Turb Operation
67 ba75491e05 04/2009
Carrying out calibration
1 Press the <M> key (long pressure) repeatedly until the Turbid-
ity measuring mode is selected.
2 Press the <CAL/ZERO> key.
The menu-guided calibration begins.
Follow the instructions on the display.
3 Insert the cell with the displayed calibration standard (here e.g.
1000 NTU/FNU) in the cell shaft (see section 4.2).
4 Align the cell:
z
Marked cell:
– Align the marking on the cell cap with the marking on the
cell shaft.
– Press and time hold the <START/ENTER> key until the
measured value is displayed.
z
Unmarked cell (see page 62)
– Press and hold the <START/ENTER> key.
– Slowly and in small steps turn the cell by one complete
rotation (by 360 °).
– After each step wait for a short time until the displayed
measured value is stable.
– Turn the cell back to the position with the lowest mea-
sured value.
5 Release the <START/ENTER> key.
Measurement of the calibration standard begins.
i
Insert standard
1000 FNU/NTU
i
Press and hold <START>
i
Align sample
Turbidity \ Calibration
i
Turb. = 1000 FNU/NTU
i
Start calibration
by releasing <START>
Turbidity \ Calibration