使火焰蔓延的最低浓度称为该燃烧物的爆炸下限，使火焰蔓延的最高浓度称为该

使火焰蔓延的最低浓度称为该燃烧物的爆炸下限，使火焰蔓延的最高浓度称为该燃烧物的爆炸上限，上限与下限之间的范围称为爆炸极限。

結果 (英文) 1:

Minimum concentration of flame spread called the lower explosive limit of the Blazers, the flames spread explosive limit for the highest concentration known as the Blazers, range between the upper and lower explosive limits.

結果 (英文) 2:

So that the lowest concentration of flame spread is called the lower explosion limit of the combustion, so that the highest concentration of flame spread is called the upper limit of the range of explosion combustion products, between the upper and lower limits called the explosion limit.