Hach-Lange DR 3800 User Manual - Manual (Page 56)

56
Standard Operations
5.5.5 Sample blank
Turbidity and color in the sample matrix can falsify the results of a
photometric analysis. The interference factors come from the
sample or are created by reactions with the reagents.
The influence of turbidity and/or color can be eliminated or reduced
by taking a sample blank reading.
In the barcode mode, a special cuvette/sample cell (LCW 919)
containing the sample blank is placed in cell compartment #1 after
the sample reading has been taken and is automatically measured.
The sample reading is then corrected by adding or subtracting the
blank value. The final result is displayed, with the message "After
blank value corr.".
Some barcode tests do not require a sample blank value to be
determined, as turbidity and color are dealt with during the test
procedure.
Note: For further information about the Help Guide (Information icon), see
Appendix B on page 143 .
5.5.6 Update/edit barcode tests
5.5.6.1 Manual update of a barcode test
Using the data provided in the barcode, the instrument
automatically sets the measurement wavelength and factors. If a
discrepancy is detected between the barcode data and the stored
data or a new test is identified, the instrument requests an update.
Data types are described in Table 5 .
Table 6 Program update options
Program point Description
Name Name of the analysis parameter
Version An abbreviation assigned by the user or the version number, etc. is entered here
Measurement process
Exact definition of the test: the number of wavelengths at which measurements are carried out,
the number of absorbance measurements needed, the keys to be used, any waiting periods
between measurements, etc.
Formula Definition of the evaluation formulas with which the test result is calculated
Variables
The number of variables shown in the display depends on the definition of the measurement
process and the formulas. Input of the numerical values of the wavelengths, factors, constants,
etc.