Eppendorf D30 BioPhotometer - Manual (Page 61)

61
Troubleshooting
Eppendorf BioPhotometer ® D30
English (EN)
9 Troubleshooting
9.1 General errors
Error Possible cause Remedy
Measuring results are
imprecise. • Reagent is past its shelf
life.
 Ensure that the reagent is still within its
shelf life and properly prepared.
• Reagent has not been
prepared properly.
 Use clean demineralized water of adequate
quality for preparation if required.
• Pipetting is not correct.  Ensure that the pipette is calibrated and
that pipetting is being performed correctly.
• Incubation procedure
before measurement is
incorrect.
 If the method procedure requires
incubation before the measurement,
ensure that the temperature and time for
incubation are correctly observed.
• The cuvette is
contaminated.
 Clean and rinse the cuvette. When
replacing a cuvette, pay attention that the
optical window of the cuvette remains
clean and that you do not touch it with your
fingers.
 If the cuvette window has become soiled
from fingerprints, wipe it clean using a
lint-free lab cloth soaked in ethanol or
isopropanol.
• The cuvette is not filled
completely with
measuring solution, and it
contains bubbles.
 Ensure that the required minimum volume
of the cuvette for a measurement is
reached and that no bubbles are in the
measuring solution.
• Turbidity of the
measuring solution.
 Centrifuge the turbid measuring solutions
containing particles and use the clear
supernatant.
• Photometer is drifting.  Contact Eppendorf Service.
 Observe the ambient conditions.
 Prevent temperature changes.
• Cuvette shaft is dirty.  Clean the cuvette shaft.