8. Mistakes to avoid

8.1 Don't spend too much time refining your estimate of the volume or mass of the flammable cloud.

In the abacus, combustion energy E is used at power (1/3). As a result, there's no point in fine-tuning the estimate of volume or flammable mass, since the effect distances vary with power mass (1/3). In other words, an error of 20% on the explosive mass only generates an error of around 6% on the effect distances.

Example:

• Volume 1,000 m ³ of propane: distance 200 mbar for an index 6 of around 51 m ;

• Volume 1,200 m ³ of propane: distance 200 mbar for an index 6 of around 55 m.

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