Abstract
We improved previous equipment to evaluate the minimum ignition energy in various oxygen concentrations. We confirmed that ignition of some substances are less sensitive with decreasing oxygen concentration. The existing empirical formula is estimated by comparing with our measurement data about the minimum ignition energy under the oxygen concentration dependence. In addition, we propose a safety measure in actual manufacturing apparatus by managing comparison between expecting electrostatic discharge and the minimum ignition energy in arbitrary oxygen concentration above the limiting oxygen concentration.
