INFICON MicroFID II Portable Flame Ionization Detector - Manual (Page 79)

074-579-P1A 79
Flame out may also occur when sampling enclosed or confined
spaces where vapors and gases cannot escape. Watch for
indications of increased flame height such as erratic readings or
sudden high concentrations followed by a flame out
fault.
If you will be using the MicroFID II in a highly contaminated area
where it is possible the oxygen content is below 10%, watch
for indications of reduced flame height such as lowered detection
limits or a flame out fault.
Cause: High concentrations of flammable gases (gases within their flammable range) are
present. High concentrations of flammable gases can act as an additional fuel
source. When this happens, the flame height may increase beyond the confines
of the combustion chamber. The hydrogen supply will then be cut off and the
flame will go out.
Action: Move to a location where there is an adequate supply of air and restart
the flame. See the information above. Watch for indications of increased
flame height such as erratic readings or sudden high concentrations
followed by a flame out fault.
Cause: Exhaust port is blocked.
Action: At low temperatures, water vapor, a by-product of the hydrogen
flame, may condense at the exhaust port. At sub-zero
temperatures, the water vapor will freeze and obstruct the
exhaust port. If the exhaust port becomes obstructed, pump
operation will be inhibited. Flame out may also result. Operate
the MicroFID II within the operating temperature range of 32°F (0°C) to 122°F (50°C).
Action: Replace the exhaust filter with a new or unblocked one. If this does not solve the
flame out issue, contact INFICON local service personnel.
Cause: Sample line is blocked.
Action: Ensure the sample line is not obstructed in any way
Cause: Inlet filter is plugged.
Action: Replace inlet filter. See Replacing Filters. See Replacing Inlet Filter section under
Routine Maintenance chapter.
Fault: Signal from zero gas is too high.
Cause: Contamination of sample line or fittings before the detector.
Action: Clean or replace the sample line or the inlet filter. See Replacing Inlet Filter
section under Routine Maintenance chapter
Cause: Span gas and zero air mixed up.
Action: Ensure clean gas is used to zero the MicroFID II. Mark the calibration and zero
gas bags clearly.