Comparison of calculated MIE against measured MIE following the conformity test procedure presented in BS EN 13821
The Minimum Ignition Energy (MIE) is defined as the lowest spark discharge energy capable of igniting a flammable dust, gas, or vapour, dispersed in air. There are various experimental methods for determining the MIE, as well as empirical formulae for estimating the MIE. The focus of this study compares estimated MIE values derived using empirical methods, against experimental results. Empirical formulae contained in BS EN 13821:2002 has been applied whilst experimental MIE data was derived following methodology also contained in BS EN 13821. For the materials considered it was noted, whilst some yield similar results, this is not true for all. Therefore, whilst the conformity test would serve as a means of test equipment validation, it is not deemed sufficiently reliable to provide data intended for practical application of any process safety measures i.e., formulating a robust Basis of Safety.