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7 Troubleshooting
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49
Problem
Cause
Remedy
■
Exclude the outlier from the calibration
curve
(see "Excluding a curve from the
.
Random calibration points
In this case, check the application:
■
Does the peak for the analyte appear at the
correct position with the correct shape?
■
Does a determination in standard solution
work correctly?
■
Are the correct reagents used?
■
Is the sample in the suitable concentration
range?
■
Is the electrode in a good condition?
The number of additions in
the method is 0.
Check the method parameter
No. of addi-
tions
on the tab
Determination
.
Calibration curve -
the calibration curve
is not linear or
poorly reproducible.
The standard additions are
outside the linear working
range.
Make sure the sample peak and all peaks for
the standard addition are within the linear
working range of the method
The peaks are not evalu-
ated correctly.
Check the baselines for all peaks and adapt the
evaluation settings if necessary (see
the baseline parameters for all curves (page
30)
Adapting the base points for an individ-
or
Pipetting has not been car-
ried out correctly.
■
The standard additions have to be carried
out by the same person using the same
pipette.
■
Read up on the correct pipetting in the
manual of the pipette.
■
Control and recalibrate the pipette.
The standard solution is
not added through the
pipetting opening.
If the electrode is removed from the measuring
solution for standard addition, the condition of
the electrode changes, and with it also the
response to the analyte can change. Therefore,
the standard solution always has to be added
through one of the pipetting openings
Summary of Contents for 2.946.0010
Page 1: ...946 Portable VA Analyzer 2 946 00x0 Manual 8 946 8003EN ...
Page 2: ......
Page 8: ......
Page 12: ...1 4 Symbols and conventions 4 Note This symbol marks additional information and tips ...
Page 79: ... 8 Technical specifications 71 8 8 Connection Connection USB version 1 1 or higher ...