Technical data

116 Operation and Maintenance Manual
Table 7 Troubleshooting Burner Issues
Problem Possible Cause Diagnosis Corrective Action
Fuses Blow on Startup Shorted heater element. Inspect for exposed wires or
broken insulation around
wire leads. Measure
resistance leads, should not
be 0.
Take Burner top off and
reseat insulation around
heater leads.
Low Sensitivity Leaks at ferrules or fittings. For SCD, use a microliter
syringe containing a small
amount of sulfur compound
e.g., CS
2
to “snoop” for leaks
while watching mV output.
Leaks are very evident by a
large increase in signal
displayed on the LED.
For NCD, a high background
could be observed from
atmospheric nitrogen.
Inspect fittings for scoring
and replace if necessary.
Replace ferrules if worn.
Hand tighten all fittings
mounted onto vespel
ferrules, and wrench tighten
all connections with Valco
ferrules.
Low Sensitivity Improper gas flows. Measure gas flows. Reset gas flows.
Low Sensitivity
High Pressure
Broken ceramic tubes or
ferrules
Remove and inspect tubes
and ferrules for chips and/or
breaks.
Replace tubes or ferrules.
Low Sensitivity
High Background
Improper column
positioning.
Inspect for charred Detector
end of column.
After cutting off charred end
of column, measure column
length 108-109 mm from
ferrule (or 114-115 mm from
bottom of nut) and re-attach
column.