INFICON MicroFID II Portable Flame Ionization Detector - Manual (Page 18)

074-579-P1A 18
You must obtain a tank of hydrogen from which you can fill the internal cylinder. When ordering hydrogen,
specify ultra-high purity hydrogen, 99.999% pure. This grade of hydrogen is also referred to as Grade 5 or
Ultra zero grade. The hydrogen must have less than 0.1 ppm hydrocarbon contamination.
You can obtain the hydrogen in various size cylinders and pressures. Specify a tank with no more than
2400 psig (16547 kPa).
The hydrogen cylinder must also have CGA 350, male outlet.
The MicroFID II Hydrogen Filling Station Part No.A1201222 is required to fill the MicroFID II hydrogen fuel
cylinder. You cannot fill the MicroFID II hydrogen cylinder without the MicroFID II hydrogen filling station.
Calibration Gas
Adequate ventilation must be provided when the MicroFID II is being calibrated.
If compound threshold limit values (TLV) are exceeded, you should use a gas bag for sampling and
calibration.
To determine the TLV of the compounds contained in the calibration gas, refer to the Material Safety Data
Sheet (MSDS) supplied with your calibration gas cylinder.
Oxygen Concentration Limits
A minimum of 17% oxygen is required to start the hydrogen flame. The 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. An oxygen deficiency will reduce the height of the flame or cause the flame to be extinguished and
may affect the displayed reading.
If the MicroFID II is used in a highly contaminated area where it is possible that the oxygen content is
below 10%, watch for indications of reduced flame height such as lowered detection limits or a flame out
fault.
Flammable Gases
High concentrations of flammable gases (gases within their flammable range) 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.
Flame out may also occur when the concentration of sample gas is so great that it causes an oxygen
deficiency. This may 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.