21
CALIBRATION
For best results, the measurement techniques must be followed during calibration. If formazin
standards are used, mix the cuvettes gently for about 1 minute and then allow the standard to settle
for 1 more minute before calibration.
Calibration can be performed in up to five points, independently, for each mode. The calibration
points are:
FNU mode:
0, 15, 100, 750
FNU
FAU mode:
15, 100, 750, 2000 FAU
NTU ratiometric mode:
0, 15, 100, 750, 2000 NTU
NTU non-ratiometric mode: 0, 15, 100, 750
NTU
Before making the calibration, assure that you are in the correct mode.
To enter calibration, press
CAL
key while in main screen. The first screen of GLP
information is displayed. Press
“Cal”
functional key to start calibration.
It is possible to interupt calibration procedure at any time by pressing
CAL
or
ESC
key.
FIRST POINT CALIBRATION
•
The first calibration point is displayed on the LCD.
This point is used for FNU and NTU modes to check the quality of the water used for dilution and to
confirm that the optical system is not dirty. In this case, if the value of the first point is over 0.15 FNU
(NTU), a warning “Cal Point1 high !” is displayed when the calibration is saved and a warning “Out of
calibration range” is displayed when measurements under 10.0 FNU (NTU) are performed.
