Blanking The Photometer 7500 Bluetooth - palintest Photometer 7500 Operation Manual

6.3 Blanking the Photometer 7500 Bluetooth

Blanking the photometer is a key first step in photometric
analysis, effectively removing the potential entrained sample
colour and minor amounts of turbidity from calculation of
analytical results.
To blank the photometer, prepare a Blank cuvette using
untreated sample i.e. sample that has not been reacted with
any reagents. If the sample is to be diluted or physically
treated (filtered for example) before analysis, use the same
dilution/treatment for the Blank cuvette.
When accessing the test method the Photometer 7500
Bluetooth will request the user to Insert Blank
Insert the Blank cuvette and press OK
The Photometer 7500 Bluetooth will determine the
absorbance due to the sample colour at all wavelengths
simultaneously and store in temporary memory for use in
analysis.
Upon successful blanking the Photometer 7500 Bluetooth will
automatically move to the Insert sample stage of the
analytical method.
If the sample is too highly coloured to support effective
blanking and subsequent analysis the error message "Error 9
is caused by the blank cuvette being too dark. Check the
correct is being used"
Ensure the blank cuvette is being used, not the sample plus
reagent cuvette. Sample colour can be reduced by dilution
with clean water; the dilution selected should take account of
the expected concentration of parameter under test.
Blank results are stored in the temporary memory of the
Photometer 7500 Bluetooth and will be used for all
subsequent tests until:

The instrument is powered down (temporary memory
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