Xylem photoLab 6100 VIS - Manual (Page 52)

Operation photoLab
®
6100 VIS
52 ba75847e01 08/2009
4.5.8 Sample blank value
By measuring and using a sample blank value, measurement errors due to
coloring and turbidity of the sample matrix can be eliminated to a large extent.
The sample blank value is a characteristic of the sample (coloration) to be
currently determined. It is determined by measuring the blank sample.
The blank sample is prepared from the sample by adding reagents to it and
is especially adapted to measurement with the test to be measured.
No chromophoric reagents, however, are added for the preparation of the
blank sample.
Note
Due to the addition of reagents the sample is diluted. This can also change
the pH value of the sample. For this reason the blank sample also has to be
diluted and the pH value adjusted accordingly.
Validity The sample blank value applies to the next measurement only.
Single and multiple
determination
The sample blank value can be determined by single or multiple
determination. With multiple determination, the sample blank value is
calculated as the median from the individual measured values.
Measuring the
sample blank value
Inserting a cell with barcode starts
a measurement.
If a cell without barcode is used:
Select the method manually
(see section 4.5.5).
Concentration
Concentration 04/16/07 9:52
Please select method for measuring
or insert a barcoded cell
or insert AutoSelector.
Setup Method list Last method New Method