Particulate Entry Lag in Smoke Detectors.
Particulate Entry Lag in Smoke Detectors.
(235 K)
Cleary, T. G.; Chernovsky, A.; Grosshandler, W. L.;
Anderson, M.
NISTIR 6242; October 1998.
National Institute of Standards and Technology. Annual
Conference on Fire Research: Book of Abstracts.
November 2-5, 1998, Gaithersburg, MD, Beall, K. A.,
Editor(s), 11-12 pp, 1998.
Available from:
National Technical Information Service
Order number: PB99-102519
Keywords:
fire research; fire science; fire suppression; smoke
detectors; time lag; sensors; signals
Abstract:
It is well known that smoke detectors do not
instantaneously respond to smoke concentration directly
outside the detector. The smoke must be transported
through the detector housing to a sensing location
inside the detector. The sensing time lag is a function
of the free stream velocity of the smoke laden air as it
approaches the detector. Previous work correlated the
detector time lag as a first-order response with a
characteristic time defined as L/V, where L is a
characteristic length and V is the characteristic
velocity (ceiling jet velocity of free stream velocity).
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899