INFICON 3000 Micro GC Gas Analyzer Operating Manual - Manual (Page 232)

9 - 4
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3000 Micro GC Operating Manual
Inverted peaks;
large, broad humps in
chromatogram Incorrect carrier gas Check the carrier gases and ensure that each
carrier gas is connected to the correct
3000 Micro GC inlet. See the 3000 Micro GC
webpage and verify proper gas setup. Refer to
section 6.4, Change Carrier Gas
Configuration, on page 6-9
.
Impure carrier gas Ensure the carrier gas purity is between
99.995% and 99.9995%.
Add hydrocarbon/moisture/oxygen traps or
particulate filters to the carrier gas line to
improve purity.
Carryover peaks If broad and sporadic peaks appear, it could
indicate carryover from a late-eluting
compound. Extend Run Time or increase
Column Temperature.
NOTE: An increase in column temperature
will change component retention
times.
Air peak on blank injection Column head pressure low Verify there is sufficient carrier gas pressure.
Insufficient carrier gas pressure may prevent
the inject valve from sealing fully, creating an
air leak.
Internal leak Contact INFICON .
Significant negative
baseline, but peaks still
appear Broken reference column Contact INFICON .
Poor separation Contamination Run a bakeout to clean the columns. See
section 9.2.2.1, Column and Detector
Bakeout, on page 9-18
.
Column Temperature and
Column Head Pressure not
optimized Reduce the Column Temperature and/or
Column Head Pressure to achieve better
separation.
Malfunctioning TCD Contact INFICON .
Malfunctioning column Check the flow coming out of the
3000 Micro GC analytical and reference
vents. If there is no flow from either or both
vents, contact
INFICON.
Table 9-1 Common chromatographic problems (continued)
Symptom Possible Cause Remedy