IMPROVED FLAME IONIZATION DETECTOR

摘要

A flame ionization detector consisting of a burner assembly (10) which includes a precombustion chamber (54) for mixing the fuel and sample gas, a combustion chamber (56) having a burner nozzle (60) for fluid communication with the precombustion chamber. An annular collector ring (70) and a spring loaded electrode collector (73) to which a potential is applied for the collection of ions are disposed in the combustion chamber (56). The collector (70) is connected to an electrometer (78) for the amplification of a current created by the migration of carbon ions to the collector (70) during combustion. Critical flow orifices (14, 24 and 34) disposed in the lines (12, 22 and 32) are used to deliver fuel gas, air, and sample gas to the flame ionization detector. The sample line (32) communicates with a bypass line (42) and capillary (44) for a passage of a major portion the sample gas directly to an exhaust vent (58).