Hach QuikChem 8500 2 Serie Mantenimiento Y Solución De Problemas página 16

Problem
The baseline is not at
zero.
The probe continues
to hit the cups.
Peaks are smaller
than the ones
received in the past.
The ammonia peaks
are very small.
Stains in the tubing
(after the heater)
when ammonia is
used
The QuikChem
method shows
support data that
cannot be made on
the system.
Flow cell leaks at
fittings or around
glass
16 English
Possible cause
For most chemistries,
• Examine the baseline in the Lachat method support data. The
the baseline will not
be at zero.
• Remove the filter and flow cell while the baseline is shown. If
Wrong sample rack
• Make sure that the correct type of rack is selected in the
Sample racks are not
• Make sure that the rack is attached correctly to the sampler
installed correctly.
• Make sure that the probe is not bent.
Probe might be bent.
• Make sure that the probe is aligned correctly with the wash
Bad reagent
• Make sure that the standard preparation, reagent preparation
Sample loop is not
• Make sure that the sample loop and the correct interference
correct
Reagent order is not
• Make sure that the transmission tubes are in the correct
correct
• Make sure that the time for sample to valve is good.
Timing is not correct
Interference filter is
not correct
The pH of the
• Make sure that the pH at the waste line is 13.
chemistry is not
• Do the QuikChem method for preparation. Make a fresh
correct
The hypochlorite is
• Make sure that the heater is set at 60 °C (140 °F) or other
expired or not made
correctly
The heater is not set
to the correct
temperature
The pH is not correct
• Make sure that there is pH at the exit of the flow cell.
• Use a reagent-grade 4–6% hypochloride solution.
Caused by the use of
household bleach
Standard and/or
• Make sure that the formulas in the QuikChem method are
reagent preparation is
not correct
• Make sure that the manifold, the interference filter wavelength
Manifold configuration
is not correct
• Look for flow problems.
Interference filter
and/or sample loop is
not correct
Flow problems
Worn out O-rings and
• Change the flow cell flares and O-rings. Use the pump to
flares
• Clean the leaked fluids off the detector and the fiber optic
baseline should be less than one volt of the support data in
the method. If the baseline increases and/or if the blank
peaks are negative, the carrier is probably contaminated.
the baseline changes significantly when either component is
removed, the issue can be the component or the installation
of the component.
software.
bath.
and shelf life are correct.
filter are located in the correct location.
containers.
solution.
temperature given in the QuikChem method.
done correctly and that the standards have been prepared
correctly.
and the sample loop are correct.
move water through the flow cell to make sure that the leak
has stopped.
cables.
Solution