It needs to be pointed out that the experimental pressure dependences shown in Figure 2 do not agree
with those resulting from the calculations of the previous sub section 2.1. This disagreement can be
explained as follows: The calculations describe UFLs based on the assumption of a perfectly adiabatic
system (no heat losses). They do not care for ignition but only for flammability (that means the ability of
a flame to propagate under the conditions investigated).