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

located onthefloor atthe door opening. At least one fire extinguisher was located near the
doomay and someone trained in fire containment was always nearby when ignition was
imminent.
3.0 R~SUltS ~~d Discussion
3.1 General Experimental Results
The results of the pwaettic experiments are further discussed in this section. The main
focus is on the ins~mented experiments and the possibility that any of the measurements
recorded can lead to pre-ignition detection.
3.1.1 Parametric Experiments
The parmetric experiments were primarily of interest for assistance in the selection of
the pans used in the instimented tests. The temperawre behavior of these tests is of some
additional interest. Figure 4 depicts the temperature versus time curves of the parametric tests
for which temperature was m~nitored. Both of the tests using stainless steel pans (shown as solid
lines) ignited, while the others which used aluminum pans (dashed lines) did not. The two tests
of diflerent amounts of com oil in a stainless steel sauce pan show similar tempera~re behavior,
except the one using the smaller mount caused compression of the curve in time. The tests of
different mounts of corn oil in a cermic-mated aluminum pan also show similar behavior
except the one using the smaller mount also caused time compression of the curve. The tests
of 250 mL of corn oil in two kinds of aluminum pans show similar behavior. Oil heated in
aluminum pans on this typical gas range fell short of ignition temperaties by at least 30 “C.
The last two parametric tests were mndudd on the open-coil electric range. The baked
beans test shows a very long water evaporation time, about 1500 seconds, until the temperature
begins to rise slmrply over 100 “C. Heating was continued for several minutes after smoke
production had decreased to a low level. The bean residue consisted of a dry char and ash. The
last test was mndu~ed using an aluminum frying pan with 250 ti of corn oil which did ignite
after approximately 12 minutes, but the temperature was not monitored. This test demonstrated
the ability of the electric range to ignite oil in a.n aluminum pan.
3.1.2 Ins~mented Experiments
A total of twenty-two tests, listed in Table 3 and consisting of twelve combinations of
range, food, and hood status, were conducted of which eighteen produced ignition and did not
experience problems with data mlle~ion or operational procedure. Seven of the test
combinations were repeated. Test one was repeated twice because the initial heating level was
too low. Tests six and seven were the only tests conducted on the smoothtop range because test
six did not produce ignition, and additional unsuccessful tests were considered likely to occur.
The reds of the ins~mentd experimen~ are provided primarily in graphical form
One test of oil heated on the electric range with the range hood off is used as a typical example
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