This report was
scanned from hardcopy.
University of Cincinnati 2010 Smoke Alarm
Symposium - Fathers for Fire Safety
The Fire Death Rate Is Essentially
Unchanged From 1977 to 2003 - US Census Bureau 2004
Photoelectric Alarms Responded
12-30 Minutes Faster Than Ionization Alarms, NOTE -
that not all Ion's Alarmed in Smoldering Tests.
"Since an individual can be set to
meet al current sensitivity standards, it is not
obvious what overall benefit is achieved from a dual
"97% of devices tested for
involvement in nuisance alarms were Ionization-type
devices." NFPA, Aherns 2004
Unwanted Activations Can Generate
a Dangerous Sense of Complacency.
"....Ionization alarms may not
always alarm even when a room is filled with smoke
from a smoldering fire...... Photoelectric detectors
can provide a lot more warning time that an
ionization detector in a smoldering fire.....
Ionization detectors can provide a little more time
than a photoelectric detector in a flaming fire...."
NIST at Boston City Council Committee on Public
"The probability of failure of the photoelectric
detector to detect a smoldering ignition is 4.06%
while the ionization detector provided a 55.8%
probability of failure in a similar type of
fire...... During a flame ignition fire, the
photoelectric smoke detector had a 3.99% probability
of failure while the ionization smoke detector
probability of failure to detect the fire is 19.8%"
Texas A&M, Department of Construction Science,
“Full-Scale Research and Testing on Fire Detection
Systems in a Residential Structure."
Journal of Applied Fire Science,
Volume 6, Number 2, 1996-97, pages 109-126, titled
“Risk Analysis of Residential Fire Detector
64 of PDF