Study of Technology for Detecting Pre-Ignition Conditions of ... - NIST

CPSC-IAG-95-1145
After generating each list, the documents were screened by title and abstract for any
potential use related to the two goals. Selected documents were read fb.r better understanding of
novel methob and designs. The screened lists are provided in Appendix A.
4.2.2 Detector Strategies
The literature and patent search for detection and sensor technology was started without
prior bowldge of what the pre-i~ition signatures might be if they existed at all. Many
conditions could be assumed based on common sense Su-ch as higher temperatures than those
experienced during safe cooking, some mount of smoke, and some increase in veiocity above
the burner due to buoyancy. The other unknown signatures left the scope of the search very
broad. The search strategies, located in Appendix B, were based. on primarily looking for smoke
and fire detector technologies and then expanding the inquiry to include other kinds of
temperature, heat, radiatio~ velocity, and hydrocarbon gas sensor technology. Upon completing
the present experimental mewurements, plume velocity and infrared imaging were not found to
be potentially usefid signatures, so their related techologim are not includd. In addition to
papers on the sensed conditions, those on the topics of smart sensors, fuzzy logic, and artificial
intelligence used in detectors were examined.
4.2.3 Controls Strategies
Control technology for shutiing down gas and electric ranges upon receiving input from
a detection device is not new or innovative. Gas burners in some applimces already have flame
sensors that cause the gas valves to close upon a “no-flame” condition. Smoothtop electric ranges
ah-eady have tiemostit-wntiolled override technology that discontinues current to the heating
elements when the cermic top temperatirm approach levels that could damage the material.
Although these tec~ologies are available in other applications than those proposed, and
itiomation was ~tiered from manufa~rers on the cument application, additional searches
were pefiormed to look for novel methods and teckologies that are applied to other equipment
or appmati, but may be utilized for these purposes.
1.S ~earc~ Results
4.3.1 Detectors
The searches for detectors and sensors resulted in the discovery of many technologies with
vqing degrees of applicability to the range pre-ignition problem. Perhaps the most valuable
resource as an overview of detector tw~ologi~ is a paper by ~osshadler.~” Some of the
major detection technologies are compared in Table 4. Smoke detectors of the ionization,
photoeltic, mndemation nuclei, and electrostatic types were investigated. These common
smoke detector teckologies are fairly simple and are a logical choice for more in-depth inquiry
since the expetimen~l results point towards smoke-relatd phenomena as the most evident
ignition precursors. Ionization detectors require a radioactive ionizing material which would
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