Hach QC8500 Series 2, Руководство пользователя

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79
Troubleshooting
6.13 Other common problems
Table 14 Troubleshooting problems
Problem type Problem description Solution
Flow related
The flow is moving
backwards. There is a blockage on the manifold. Refer to section 6.5 on
page 73 .
Chemistry and/or Flow related
Air bubbles are coming
out of the heater block,
but no air is getting into it.
Degas all reagents with helium unless otherwise indicated in the
QuikChem method. A back-pressure loop may be used to keep
the air in solution. Refer to
section 6.3.1 on page 64 for
instructions on making a back-pressure loop. If the problem only
occurs with samples, this might be due to the presence of
carbonates. Do a carbonate test on some samples by adding
few drops of 1 M HCl. If some foam or effervescence is visible,
treat the samples to eliminate the carbonates.
A puncture on the heated tubing wrapped on the heater mandrel
could introduce air bubbles. Turn the heater off and allow it
some time to cool. Run some standards to see if the air bubbles
persist. If this is the case, rewrap the heated coil using Teflon
tubing 0.032" ID.
Chemistry and/or Flow related
A white precipitate is
formed inside the manifold
tubing when running TKN.
Run a strong solution of sodium hydroxide through all the
manifold reagent lines to remove the precipitate. If the
precipitate is not removable, rewrap the entire manifold and
heater. This chemistry requires running buffer solution before
any of the other reagents.
Avoid any precipitate—Place all the reagent lines in deionized
water before running any reagents. Turn the pump on at speed
of 35. Run the water for one minute. Place the buffer line in the
buffer container. Run the buffer for a couple of minutes. Put the
rest of the reagents in line. When the chemistry run is complete,
remove the buffer line last and put in the deionized water rinse
container.
The buffer in the TKN method is very close to saturation. If some
crystals are formed in the bottom of the container, try remaking
the buffer by adding the reagents in the following order:
1 Dissolve the sodium phosphate dibasic heptahydrate in the
water.
2 Add the disodium EDTA and stir until dissolved. The
solution will be slightly turbid.
3 Add the sodium hydroxide and dissolve completely by
shaking or stirring.
Software and/or Hardware
related
The diagrams and reports
show areas but no
concentrations for all
samples.
The system has not been calibrated. The Calibration Results
show the calibration curves for the channels run.
Software and/or Hardware
related Sampler fails to initialize
to wash.
Before attempting to troubleshoot this problem, make sure the
system has the latest version of software installed. This problem
could be caused by the sampler itself or a loose sampler cable.
Read
section 3.3 on page 21 .