Performance of a Planar Micro-Flame Ionization Detector

Abstract:
The flame ionization detector (FID) is the preferred method of hydrocarbon detection. Unfortunately, it is operated at high fuel and oxidant gas flow and therefore not suitable for portable applications. This work presents an FID miniaturized by means of MEMS technology (muFID) to reduce gas consumption. Before, the minimum detectable limit (MDL) of the muFID used to be a factor 20 above what can be expected from conventional FIDs. This paper presents two approaches that lead to improved device performance. First, the fuel gas flow is increased, which results in larger flames with higher ionizing power and a reduction of the MDL by a factor 1.24. Then, premixing the sample gas with the fuel gas, instead of separate sample gas supply, allows for a further reduction of the MDL by a factor 2.12.