The SERVOPRO HFID heated total hydrocarbon analyzer utilizes a highly sensitive Flame Ionization Detector (FID) for measuring volatile hydrocarbon concentrations in vehicle/engine certification testing and industrial gas stack emissions monitoring applications. This ensures real-time, on-stream gas stream analysis, unlike gas chromatography (GC) based analyzers, which require batch sampling.
To measure methane (CH4) and non-methane hydrocarbons (NMHC), an oxidation catalytic converter is used to allow methane to pass through untouched to the FID detector, while all other hydrocarbons are oxidized to CO2. This non-methane cutter (NMC) assembly contains the heated catalyst, which removes all but the methane content of the sample gas. The cutter temperature is set to about 250°C, which is well below the oxidation temperature of CH4, and is optimized during factory calibration.
The oven temperature of the HFID analyzer for the gas sample itself is adjusted at the factory to be controlled at 190°C to ensure that any heavy hydrocarbons (C5 and above) present in the emission stream are kept in the gas phase. The sample gas is maintained at this elevated temperature until it exits the FID bypass, thus preventing any loss of hydrocarbon concentration in the sample due to condensation. The heated sample gas is maintained at this temperature by a self-contained internally adjustable temperature oven.
