wtw Turb 355 IR/T, Operating Manual

Page: 26 / 44

Operation
66
4.3.5 Partial (user-defined) calibration
You can also calibrate the instrument using two or only one
calibration standard. When doing so, please follow the notes
in 4.3.2 C
ALIBRATION PROCEDURES
.
1 Switch on the turbidimeter: Press the
0
key.
2 Press the
g
key. CAL and a flashing 1000 appear on
the display. This indicates that you should insert the
1000 NTU/FNU calibration standard.
3 If required, select another calibration standard (10.0
or 0.02 NTU/FNU) with the
8
or
2
key.
4 Insert the selected (flashing) calibration standard in
the cuvette shaft so that it clicks into place.
5 Press the
1
key and align the cuvette as
described on page 55.
After releasing the
1
key a 30 or 60 seconds
countdown is displayed. The instrument measures
the calibration standard and afterwards shortly
displays the nominal value of the calibration
standard. Then the prompt to insert the next lower
calibration standard is displayed.
6 If required, select another calibration standard with
the
8
or
2
key (the display of the respective
calibration standard flashes).
7 Repeat steps 4 to 6 until all required calibration
standards have been measured.
3
2
1 ERR
4
1 0 0 0
NTU
FNU
CAL