Thermo Scientific Mercury Freedom 80i Manual page 63

Thermo Fisher Scientific
Malfunction
Poor oxidation, low total
mercury reading during
oxidizer test
Slow total channel recovery
after Cl valve is ON
2
Poor oxidation, elemental
mercury reading stays high
Possible Cause
Contaminated filter
Calibration gas not
transported by heated line
Cl valve or Hg valve not
2
opening
Leak in the Hg or Cl valve
2
to the oxidizer (in probe)
Quartz wool in either the
inlet or exit fitting of the
converter tube (affects
total efficiency)
Cl orifice plugged
2
Troubleshooting
System Troubleshooting Guides
Action
required.
If the probe has been running in a
stack for more that 6 months
without any preventive
maintenance, remove and clean
the filter in an ultrasonic bath or
replace it.
The elemental mercury calibration
gas generated by the Model 81i,
should be transported to the
probe using a 3/8-inch heated
PFA line (line #3 in the supplied
umbilicals).
Check the wiring of the umbilical
to the probe (check valve
grounding).
Using an appropriate flowmeter,
check the flow of both Hg and Cl
to the inlet of the oxidizer while
in oxidizer mode (note that the Cl
valve has a 15 minute delay). For
s/w versions 01.00.21.231 or
later, this delay can be adjusted.
Ensure that the 82i is
communicating with the 80i and
opening the valves when
required. On the 82i interface
board, the left most LED indicates
that power is being sent to the Hg
nd left most LED
valve. The 2
indicates that power is being sent
to the Cl valve.
2
Ensure that the tubing and fittings
on both the inlet and outlet of the
Hg valve are leak tight.
(Specifically check the 2-inch
piece of Teflon tubing that
connects valve 4 to valve 6.)
Shut the sample pump OFF,
remove both the inlet and outlet
fittings from the converter tube,
and ensure there is no quartz
wool in the fittings or tubing. If
there is, clean and replace.
Using a flowmeter (with
appropriate Cl compatible
2
material), measure the flowrate
of the Cl after the regulator and
2
Mercury System Manual
2
2
4-17