500 D 01/2012
14a
Measurement with factor
1. Select method 901
2. The preset wavelength is displayed. Select the required wavelength using keys
U
/
U
and confirm the selection by pressing
OK
. The selected wavelength is
automatically adjusted.
3. Enter factor via keyboard. The accuracy of the display is determined by the num-
ber of decimal places of the factor.
4. Perform measurement following the instruction of the display. (After measure-
ment, as long as the cuvette is still in the cuvette slot, the extinctions can be
displayed by pressing
.)
5. Return to method selection using key
ESC
.
The factor is erased.
3.4.2 902 STANDARD
There are certain determinations, where the color reaction strongly depends on
different parameters, such as temperature, time or concentration of the reagents
(e.g. medications). In such cases it is necessary to analyze a standard with a known
concentration, as well as the test sample. The test results are then related to those
of the standard. The Lambert-Beer Law (E
1
:
β
1
= E
2
:
β
2
), must apply here once
again as follows:
unknown concentration = concentration of standard
.
extinction (test sample)
extinction (standard)
Measurement with standard
1. Measurement with standard 902
2. The preset wavelength is displayed. Select the required wavelength using keys
U
/
U
and confirm the selection by pressing
OK
. The selected wavelength is
adjusted.
3. Enter concentration of the standard via the keyboard. The accuracy of the dis-
play is determined by the number of decimal places of the standard concentra-
tion.
4. Perform measurement following the instruction of the display. (After measure-
ment, as long as the cuvette is still in the cuvette slot, the extinction can be
displayed by pressing
.)
5. Return to Method selection using key
ESC
.
The standard concentration is erased.
