Measurement of minimum ignition energy in hydrogen-oxygen-nitrogen premixed gas by spark discharge

We have measured the minimum ignition energy (MIE) of hydrogen-oxygen-nitrogen premixed gas by spark discharge. The gap distance of point-point electrode was changed between 0.3 and 1.0 mm. The effects of hydrogen and oxygen concentrations on the MIE were measured. It was 0.006 mJ for H2 with O2 / (O2+N2) = 0.35 mixture, while it was 0.017 mJ for H2 with dry air mixture. For H2-O2 mixture, it was below 0.004 mJ, which was not precisely measured due to the limitation of our measurement.