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Troubleshooting
Troubleshooting Guides
6-6
Model 48i Trace Level-Enhanced Instruction Manual
Malfunction
Span calibration coefficient
outside acceptable limits of
0.5 – 2.0.
Excessive response time
Analog signal doesn't match
expected value.
Pressure transducer does not
hold calibration or is noisy
No output signal (or very low
output)
Run output noisy
Possible Cause
Bad span gas
System leak
Insufficient calibrator flow
Averaging time is not set
correctly.
Instrument is not drawing in
sample at normal flow rate.
Software has not been
configured.
Recorder is drawing down
output.
Pressure transducer
defective
No sample gas reaching the
analyzer
Ruptured pump diaphragm
Blocked sample capillary
Recorder noise
Sample CO concentration
varying
Foreign material in optical
bench
Action
Verify quality of span gas.
Perform leak test.
Verify calibrator is providing
a flow of at least 1.0 LPM.
Go to Averaging Time (Main
Menu) and verify setting.
Check sample Flow and
Pressure readings on the
Diagnostics 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 in the
"Preventive
Maintenance" chapter.
Verify that the selected
analog output has been
properly configured to match
the data system.
Verify that the recorder or
data logger input impedance
meets minimum
requirements.
Replace pressure transducer.
Check input sample flow
Rebuild pump head
Clean or replace capillary
Replace or repair recorder.
Run instrument on a span CO
source - if quiet, there is no
malfunction.
Clean optical bench.
Thermo Fisher Scientific
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Troubleshooting
