Diode laser measurements of HF concentrations produced from heptane/air pan fires extinguished by FE-36, FM-200, FE-36 plus APP, or FM-200 plus APP

Tunable diode laser absorption spectroscopy (TDLAS) is used to measure the time evolution of hydrogen fluoride (HF) concentrations produced from a ser ies of enclosed heptane/air pan fires extinguished by either FE-36, FM-200, FE-36 plus ammonium polyphosphate (APP, or FM-200 plus APP. For the fires studied, the change in HF gas concentration with time is dependent upon the fire-fighting chemical used to extinguish the fire. The presence of APP is observed to reduce HF concentrations in the fire enclosure. Visible attenu ation spectroscopy is also used to measure the amount of light attenuation (obscuration) that occurs as a hand-held fire extinguisher containing powde red fire fighting agent is released in the crew; space of a M1-Abrams land combat vehicle.