Eppendorf D30 BioPhotometer - Manual (Page 65)

65
Troubleshooting
Eppendorf BioPhotometer ® D30
English (EN)
9.3 Result flags
Warnings and error messages for results are displayed in the bottom right of the help box. The header bar
of the Help box is highlighted yellow for warnings and red for error messages.
Warnings: Decide whether the result is useful for you while taking the displayed warning into
consideration.
Error messages: No result is displayed; the reason is shown in the error message.
Problem Cause Solution
The standard curve
is not monotone.
Please select
another Curve Fit. • No usable result was returned during
the evaluation of a standard curve
using the "spline interpolation",
"quadratic regression" or "cubic
regression"
Curve Fit procedures.
 Select a different Curve Fit
procedure.
Some absorbance
values for
secondary
wavelengths are too
high or are not
displayed. • For at least one secondary
wavelength, the absorbance exceeded
the measuring range.
• Secondary wavelengths are not
needed for calculating the
concentration result. They are used
for different purposes. For example,
dsDNA method: absorbance at
280 nm for the calculation of
ratios
260/280.
• Turbidity of the measuring solution
• Measurements at the limits of the
photometric measuring range.
 If the absorbance values of the
secondary wavelengths are relevant:
Dilute the sample or remove the
turbidity via centrifugation and repeat
the measurement.
The result is
outside the range of
the standard
concentrations. • For methods with evaluation via
standard curves (nonlinear evaluation
method): The sample result is up to
5 % outside of the standard
concentration range.
 Accept the measurement result, or
remeasure the sample under
conditions under which the result is
within the range of the standard
concentrations (dilute sample or
modify standard concentrations and
remeasure).
The coefficient of
determination is
<0.8. • For methods with evaluation of
standard series via the regression
procedure: The coefficient of
determination for the regression
evaluation indicates a significant
deviation of the measuring points
from the regression line.
• Turbidity of the measuring solution.
• Measurements at the limits of the
photometric measuring range.
 Accept the result of the standard
evaluation or remeasure the
standards.
 Make sure the measuring solutions
are clear.