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Thermo Scientific
Problem
Instrument appears to zero,
but there is weak or no
response to span gas
Possible Cause
Hydrocarbon kicker has
failed
High scattered light
Span cylinder empty
Calibration system failure
Flow rate of the diluted
span mix is adequate
Instrument is not drawing in
span gas
SO
is being absorbed by
2
tubing, filters or dirt in the
calibration system
Flash lamp has failed
PMT has failed
Troubleshooting
Troubleshooting Guide
Action
Replace the hydrocarbon kicker.
Toggle the "Flash Lamp" off in
the Settings>Measurement
Settings>Advanced
Settings>Flash Lamp screen. If
the previously high signal drops
to zero or less when the flash
lamp is off, the problem may be
caused by scattered light from
dust in the optical bench. If so,
carefully clean the bench.
Check the source pressure.
Check solenoids or other
hardware to be sure that span
gas is being delivered.
Check by-pass or atmospheric
vent to verify that the zero air
system is providing more flow
than the instrument draws.
Check the sample flow and
pressure in the Settings>Health
Check>Status and Alarms>Flow
and Pressure screen.
Use an independent flow meter
to check flows at the sample
inlet and exhaust bulkheads
(they should match).
Perform a leak test as
described on page 5-5.
Replace any lines made of vinyl
or plastics with fresh PTFE or
stainless steel. Replace PTFE
filter membranes that look
dirty. Remove any filters that
are not PTFE membranes.
Listen for the rapid clicking of
the flash lamp. Check the flash
lamp voltage and intensity.
Check the PMT voltage and run
the optical span test. A good
optical span test indicates that
the PMT is OK and that the
problem is more likely the
lamp. Adjust PMT voltage if
43iQ Instruction Manual
6-3
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