22
CALIBRA
TION
11.2. CALIBRATION PROCEDURE
For best results follow correct measurement techniques.
When calibrating using formazin standards, gently mix the cuvettes for 1 minute and allow the
standard to settle for another minute before calibrating.
Calibration can be performed in two-, three-, four-points.
To stop calibration, press CAL or ON/OFF key.
Two-Point Calibration
1. Press the ON/OFF key turn the instrument ON. Dashes indicate the instrument is ready.
2. Press CAL key to enter calibration mode. “CAL” tag is active throughout the calibration procedure.
LCD displays “CAL P.1” and no suggested value. This first point is used to check the optical system.
3. Insert the <0.1 FNU standard cuvette into the holder and ensure that the cuvette mark is
aligned with mark on top of the instrument.
4. Close the lid and press READ
. The display will show blinking dashes and the icons for cuvette,
detectors and LED will appear during measurement.
Alternatively, press LOG/CFM to skip the first point.
5. The second calibration point (15.0 FNU) is displayed on the first line, “CAL P.2” on the second
line with READ tag blinking.
<0.1
FNU
6. When calibrating with formazin, press GLP
or AVG
keys to edit displayed value until correct.
7. Remove the first standard cuvette and insert the 15.0 FNU standard cuvette (or the prepared one)
into the holder and ensure that the cuvette mark is aligned with the mark on top of the instrument.
8. Close the lid and press READ
. The display will show blinking dashes and the icons for cuvette,
detectors and LED will appear during measurement.
