Citation

Wieser D, Jauch P, Willi U. Fire Safety J. 1997; 29(2-3): 195-204.

Copyright

(Copyright © 1997, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

We have measured the pressure dependence of fires similar to those of the European standard fires at altitudes above sea level from 400 m (970 mbar) to 3000 m (710 mbar) in a mobile test room of reduced size (6 x 2.8 x 2.1 m). At all altitudes combustible parameters were kept constant. We recorded standard parameters, in particular optical extinction m, the y-value of the standard ionization chamber and increase in temperature [Delta]T, as well as CO, CO2 and O2 concentrations. With decreasing outside pressure fires develop more slowly. Our data show a dependence of burning rates on pressure as [is proportial to]p[is proportial to] where a [approximate] 1.3. Whereas maxima of [Delta]T and change of CO2 concentration show no significant dependence on pressure, maxima of extinction m decrease by [alpha] factor of 2.7 +/- 0.2 (polyurethane foam fire) or 2.2 +/- 0.2 (n-heptane fire) with pressure decreasing from 970 to 710 mbar. At this maximum pressure change, decrease of 'smoke density' y is smaller. However, m/y ratios remain constant up to an altitude of 1800 m.