Fire Detection Using Reflected Near Infrared Radiation and Source Temperature Discrimination.
Fire Detection Using Reflected Near Infrared Radiation
and Source Temperature Discrimination.
(3256 K)
Lloyd, A. C.; Zhu, Y. J.; Tseng, L. K.; Gore, J. P.;
Sivanthanu, Y. R.
NIST GCR 98-747; 43 p. April 1998.
Sponsor:
National Institute of Standards and Technology,
Gaithersburg, MD
Available from:
National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
Telephone:
1-800-553-6847 or 703-605-6000;
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Website:
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Order number: PB98-146145
Keywords:
infrared radiation; fire detection; radiative heat
transfer; temperature
Abstract:
A new type of near infrared (NIR) fire detector which
utilizes a statistical analysis of apparent source
temperatures of fires was developed. The NIR fire
detector measures the spectral radiation intensities
emanating from fires at 900 and 1000 nm. These
measurements are used to obtain and a time series of
apparent source temperatures. The near infrared
radiation characteristics of five standard test fires
specified in the guidelines of the European Committee
for Standardization were measured and utilized to
develop a fire detection algorithm. The five test fires
specified in the guidelines involved a heptane pool, a
polyurethane foam, a wooden crib, a smoldering cotton
and a smoldering wood. The normalized power spectral
density of the spectral radiation intensity at 900 or
1000 nm combined with the probability density function
of the apparent source temperatures are sufficient to
determine the presence of the test fires in the vicinity
of the detector. The NIR fire detector was evaluated
for sensitivity to both direct and reflected radiation
from the five test fires. When direct radiation is
incident on the NIR fire detector, four of the five test
fires were always detected. The smoldering wood fire
was detected only if the NIR fire detector was very
close. The NIR fire detector can also detect the
heptane pool, the polyurethane foam and the wooden crib
fires from reflected radiation. The response time of
the NIR fire detector ranged from approximately 1 to 4
minutes for the open fires. The NIR fire detector had
no instances of false alarms during the test period.
The response time can be shortened considerably (to a
few seconds) by using a programmable DSP chip rather
than a personal computer. We continue to seek SBIR
funding for developing this faster version.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899