Problem
Cause
Solution
Negative values/no
No sample.
1. Add Sample to solution
absorbancy
Cuvette light path
2. Check cuvette window
orientation incorrect.
orientation.
Wrong wavelength setting.
3. Check assay wavelength
requirement.
May have blanked the
4. Reblank the instrument using
instrument using sample
buffer or water.
instead of blank solution.
Cuvette window "Z"
5. Use only 8.5 mm "Z"
height incompatible with
dimension cuvettes.
cuvette chamber.
(See Section 12.4.)
Fluctuations
Interference in light path.
1. Check that there are no
scratches on the cuvette.
2. Check that there are no
particles floating in the
cuvette.
3. Wipe the cuvette walls with
lint-free tissue.
4. Make sure the sample is in
the recommended working
range i.e. 0.1–1.5 AU.
Section 10
Maintenance
10.1 Cleaning Up a Fluid Spill
In case of a spill in the cuvette chamber, clean up the spill using the following procedure:
1. Turn the instrument off and unplug the power cord.
2. Use a syringe to clean the cuvette chamber.
3. Use a cotton swab to dry the cuvette chamber.
4. Dampen cloth with water. Use it to clean the instrument from the outside, including the
display and the keyboard.
10.2 Cleaning Quartz Cuvettes
Wash cuvettes using a dilute alkaline solution such as 0.1 M NaOH and a dilute acid such
as 0.1 M HCl. Rinse cuvettes several times with distilled water. Always use clean cuvettes
before taking absorbance measurements.
Rigourous cleaning may be required after using difficult samples. In such cases follow the
manufacturer's instructions and use a suitable detergent to clean the cuvettes.
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