Freeburn

Underwriters Laboratories Inc. 2 showed that rate-of-rise or rate-anticipating thermal detectors spaced as little as two feet or six feet directly above a 2½-square-foot alcohol fire, after a freeburn of 30 seconds, either did not detect at all within 30 seconds or, did so between 28 and 30 seconds.

These time intervals, commencing with the completion of the incipient time period, were then referenced on a freeburn fire growth curve generated by Lee for this type fuel array, and the associated convective heat release rate determined.

Envirogel was only tested against two scenarios due to agent distribution system problems. Freeburns of each fire scenario and the individual component fires were also evaluated.

In general, the scatters for all the above measurements were within those observed in freeburn crib fires.