Hach LXV320.99.00001, Руководство пользователя

Страница: 23 / 36

23
Section 5 Operation
5.1 Calibration
Turbidity measurements do not need to be calibrated, as a standardized calibration curve
according to ISO 7027 is stored in the instrument. It is possible to create a
customer-specific calibration of the turbidity curve. If the standard curve has been altered,
a star (*) appears before the measurement point.
Solids measurements must be calibrated on site. It is not possible to define a general
standard for this as the type and composition of the solid particles can differ greatly.
5.1.1 Important notes for calibration
Calibration containers
In order to avoid reflections of the measurement beam on the base and walls of the
container, a black—or at the very least dark-colored—container should be used for
calibration.
The probe can also remain in the tank so long as a representative laboratory sample can
be taken at this point.
Measured variable (homogeneity)
100% represents a homogeneous measurement medium. After approximately
10 seconds, this measured variable provides a representative statement about the
homogeneity of the measurement medium. The homogeneity is displayed as a
percentage value after an individual measurement (
Figure 8 ).
Replacing the probe
As the calibration is carried out for the measuring system (meter and probe), only the
probe supplied may be used for the measurements. If a different probe is used, the
equipment must be recalibrated.
Note: If you have changed the probe, the error message "Incorrect probe" is displayed. Register the
new probe under
MENU > SYSTEM
with the code 390 (see section 3.4.1, page 14 ). This releases all
the calibration curves for the solid matter measurement. The instrument then needs to be
recalibrated.
Figure 8 Homogeneity in %
1 Homogeneity