INFICON MicroFID II Portable Flame Ionization Detector - Manual (Page 82)

074-579-P1A 82
Problem: Sample flow rate varies from 600 ml/min. +/- 10%.
Cause: Inlet filter has not been installed.
Action: Install an inlet filter into the inlet filter cap.
Cause: Inlet filter cap has not been tightened onto the detector cap.
Action: Finger-tighten the filter cap.
Cause: Inlet filter is plugged.
Action: Replace the inlet filter
Cause: Pump has been damaged.
Action: Contact the Service Department.
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: The exhaust frit has become plugged. Contact the Service
Department.
Problem: Flame will not ignite.
Cause: The hydrogen gas has run out.
Action: Ensure the shut-off valve is open.
Action: Refill the hydrogen cylinder if necessary.
Cause: Oxygen supply is deficient.
Action: Ensure there is an adequate supply of oxygen. Do not attempt to ignite
the flame in a location where there is greater than 10,000 ppm methane
or the equivalent concentration of a flammable gas. Move to a location
where there are lower concentrations and start the flame and then begin
sampling higher concentrations.
If the flame goes out while you are sampling very high concentrations, it
is possible that you are sampling above the flame out concentration.
The flame out concentration for methane is approximately 52,000 ppm
(5.2% methane in air).
A minimum of 17% oxygen is required to start the hydrogen flame.
Oxygen is supplied from the sample as it is drawn in by the pump. A
minimum of 10% oxygen is required to maintain the hydrogen flame.