Video Detection and Monitoring of Smoke Conditions.
Video Detection and Monitoring of Smoke Conditions.
(81 K)
Cleary, T. G.
International Conference on Automatic Fire Detection
"AUBE '04", 13th Proceedings. University of Duisburg.
[Internationale Konferenz uber Automatischen
Brandentdeckung.] September 14-16, 2004, Duisburg,
Germany, Luck, H.; Laws, P.; Willms, I., Editor(s)(s),
681-690 pp, 2004.
Keywords:
fire detection; fire detection systems; smoke; detection
limits; smoke obscuration; exit signs; visibility;
experiments; lighting equipment
Abstract:
Initial tests have been performed to assess detection
limits and smoke obscuration monitoring for a video
scene under different lighting and smoke concentration
conditions. An illuminated exit sign located in the fire
emulator/detector evaluator duct was used as the scene.
A fixed gain, black and white CCD camera, coupled to a
manual-focus, manual-iris video zoom lens was used. The
lens itself was attached to a rigid boroscope, which
penetrated the duct and viewed the exit sign from a
distance of 2 m. Flaming soot, smoldering wood smoke,
and ISO test dust were used to obscure the scene.
Repeated tests were performed with the external scene
lighting turned on or off. Scenes ranged from smoke/dust
free conditions to a completely obscured exit sign.
Analysis of the data shows that a CCD camera pointed at
a continuously illuminated source, like an exit sign,
can provide an indication of obscuring aerosols in the
scene (i.e. detection). Furthermore, an assessment of
the visibility conditions can be obtained from the scene
under fixed lighting conditions. Analysis of the loss of
contrast between the
illuminated letters and the background of the sign
provides a more general assessment of visibility
conditions.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899