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Troubleshooting
System Troubleshooting Guides
Troubleshooting -
Miscellaneous
4-18
Mercury System Manual
Malfunction
Low total efficiency
Prior to System Integrity
test, baseline Hg reading is
not flat
High 80i pressure
Table 4–9 describes possible malfunctions and provides the recommended
action to take to restore the system to normal operation. When a reference
to a manual is included in the Action description, go to the associated
manual, such as the 80i or 81i, not this "Mercury System Manual."
Table 4–9. Troubleshooting – Miscellaneous
Malfunction
Possible Cause
Excessive noise
Defective or low
or spikes on
sensitivity PMT
analog outputs
Defective input board
or BNC connection
Noise pick-up by
recorder or data logger
Excessive
Averaging time is not
response time
set correctly
Instrument is not
drawing in sample at
normal flow rate
Hg is being adsorbed
and/or released by dirt
Possible Cause
Mercuric chloride is being
lost on cold spots
oxidizer not fully purged
from previous test
Leaks in tubing
Action
With previous coefficients and PMT voltage
known, introduce a known concentration of span
gas.
Identify the defective component and replace.
Check analog cable shielding and grounding.
Try to localize source of noise by comparing
analog signal to data collected through RS-232
or Ethernet.
Go to Averaging Time (Main Menu) and verify
setting (should be one minute).
Check sample flow and pressure readings
(Diagnostics menu).
Use an independent flow meter to check flows
at the Hg(0) or Hg(t) inlet and exhaust bulkheads
(they should match). Instrument should be in
Manual mode with either Hg(0) or Hg(t) selected.
Perform a leak test.
Replace any lines made of vinyl or other plastics
with fresh Teflon. Replace Teflon filter
Action
orifice assembly. If there is low
flow or no flow, clean orifice in
an ultrasonic bath or by
pressurizing orifice with water.
Check probe insulation and repair
as necessary.
Increase Post Condition duration.
Check probe tubing for leaks and
repair as necessary.
Thermo Fisher Scientific
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Table of Contents
Troubleshooting
