Search Results

The Flame Ionization Detection (FID) is the most sensitive and widely used technology for the measurement of total hydrocarbons (THC). In the automotive emission testing of hydrocarbons, the fuel used for the flame in the FID analyzer is a mixture of hydrogen and helium in the ratio of 40:60. The Environmental Protection Agency (EPA) revised 40CFR part 1065 in April 2014 to include nitrogen as a balance gas alternative to helium for FID fuel mixtures used in the automotive industry. In addition to the balance gas alternative, the FID fuel blend tolerance was decreased from 40±2% to 40±1% (0.39 to 0.41mol/mol) hydrogen to minimize the impact on analyzer response. The feasibility of nitrogen as a FID fuel balance gas was studied and compared with a helium balance gas to understand the relative impact on emission testing. The study evaluated multiple hydrogen concentrations ranging from 38-42% in both balance gases.