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

CPSC-IAG95-1145
Appendix A also contains a section on fuzzy logic, artificial intelligence, and smart sensors as
applied to multi-parameter detection. The algorithms and hardware can range from simple to
.
very sophisticated and would depend on the final design of the detector. The number of inputs
.“ to the smart system and how they should be interpreted would impact the complexity and cost
of the detector. Costs of the individual components have not been assembled because they are
. ,. so dependent on actual design and application.
4.3.2 Controls
Very few of the documents found in the NTIS and EI databases were directly related to
the needed technology, but many of the patents were similar to or exactly the kinds of controls
being sought. Several of the patents are for power disruption devices designed for smoke or fire
ahum input. Other patents are for gas safety valves with detector inputs. Brochures that were
obtained from companies advertise similar technology to that which was sought. The technology
for shutting down gas and electric ranges as ignition conditions are approached is readily
available and is relatively inexpensive since much of it is mass produced for application to ranges
and other appliances.
5.0 Conclusions
The conclusions pertaining to the experiments are based on measurements and
observations of combinations of specific ranges, pans, foods, and ventilation so extrapolation to
other condhions should be pefiormed with caution. The conclusions of this research are as
follows:
● Food cooked in a stainless steel pan more quickly reached ignition conditions than the
same food cooked in an aluminum pan.
● For the particular open-coil element electric and high-output gas ranges used in these
experiments, food cooked on the electric range reached ignition conditions more quickly
than the same food cooked on the gas range with the exception of sugar which reached
ignition conditions more quickly on the gas range.
● For the particular ranges used in these experiments, cooking food on the electric range
produced similar ignition conditions to those produced by cooking the same food on the
gas range.
● The temporal heating and ignition behaviors of soybean oil and bacon were simila~
however, sugar had a unique behavior.
● The particular range hood used was not found to have a significant effect on ignition
conditions, and its active or inactive status appeared irrelevant to pre-ignition detection.
● Weak indicators and non-indicators of impending ignition were velocity above the burner
and infrared imaging of the cooking area.
● Strong indicators of impending ignition were food, pan, range, and range-hood
temperatures, smoke particulate, and hydrocarbon gases. Some pre-ignition temperature
signatures will require more study since they may be mimicked by normal, safe use of the
oven or multiple burners.
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