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Effect of Water Sprays on Fire Fighter Thermal Imagers.

pdf icon Effect of Water Sprays on Fire Fighter Thermal Imagers. (596 K)
Widmann, J. F.; Duchez, J.

Fire Safety Journal, Vol. 39, No. 3, 217-238, April 2004.


fire fighters; water sprays; thermal imaging; fire fighting; infrared imaging; sprinklers; extinction; attenuation; large scale fire tests


The performance of fire fighter thermal imagers through water sprays has been investigated experimentally and theoretically. Thermal imagers are finding increasing use in fire fighting applications, and the ubiquitous nature of fire sprinklers, water mist suppression systems, and water curtains for radiation attenuation necessitates a thorough understanding of the effect of water sprays and mists on thermal imager performance. Laboratory-scale and full-scale evaluations of thermal imager performance through water sprays have been conducted, and the results analyzed using Mie theory to predict the extinction of radiation by water drops. Imagers were found to perform satisfactorily even through water sprays produced by sprinkler nozzles with K-factors. Tests were conducted under non-fire conditions; thus, the effect of interaction between water sprays and a hot smoke layer on imager performance was not investigated.