Knauer K-7400S - Measurement Calibration Process

Semi-Micro Osmometer K-7400S instructions, V3700
Operation 22
7.7. 2 Measurement calibration
Normally a two-point calibration is sucient.
Note: Calibrations must be performed very carefully. A confusion of the
calibration solutions will aect all later measurements and leads to incor-
rect results.
Up to 3 calibration points are possible. The desired calibration concentra-
tion can be selected on any of the fields. After that, the calibration run is
started by pressing the <START> button.
The first field is fixed on „0000“. On the other fields the choices are ----,
%%%%, 50, 100, 150, up to 1900, 1950, 2000 in steps of 50 mOsmol / kg.
Selecting „----“, the corresponding calibration point will be deactivated.
The selection of „%%%%“ deactivates all other calibration points (except
„0000“). Simultaneously the displayed measurement results will be shown
in % of this calibration point instead of „mOsmol / kg“. The measurement
results are now displayed in % of this calibration value.
Note: At least two calibration points must be active, the „0000“ and one
of the others.
The calibration point remains active until a new valid value for the selec-
ted field is created on the CALIBRATE screen. If a calibration run is not
suc cessfully finished the last calibration value becomes reactivated.
At least 2 calibration points are necessary for regular measurements. To
determine the measurement results, it will be interpolated between the
closest calibration points, or extrapolated from there.
Note: It is recommended to choose the calibration solutions so that
the expected measurement values are situated between the calibration
points.
Performing the calibration
Prepare a measurement with water (HPLC quality, see „7.6.1 Measure-
ment preparation process“ on page 20).
1. Activate the CALIBRATE screen and set the first calibration field to
„0000“.
2. Push the <START> button. The run can be interrupted at any time by
pressing the <STOP> button. While the calibration is running, the
screen displays the sample temperature and the elapsed time.
0000 mOsmol > +5.43 ° C
1:23
3. After the measurement is successfully completed, the measurement
value is displayed.
0000 mOsmol > -0.00 ° C
o.k.? <start>
Push the <START> button for confirmation. An earlier measured cali-
bration will be overwritten. By pushing any other button, the new
Prerequisites
Process