Performance of Home Smoke Alarms - National Institute of ...

Figure 85 shows the smoldering rod fabricatedfor theses tests. The rod material was ceramicthrough which nichrome wire was enclosed. Thetotal length of wire was about 0.76 m (30 in) Aloop was formed by the wire at the end of therod. The diameter of the loop wasapproximately 0.13 m (5 in). The wires wereconnected to a variac to control the voltage (andthus the current applied) to the loop.Smoldering was initiated with a low current thatwas slowly increased as necessary to insuresufficient heat to sustain extended smoldering ofthe polyurethane foam. Typical heat output was Figure 85. Rod used for smoldering ignitionsapproximately 0.2 kW A thermocouple,attached to the top surface of the seat cushion or mattress above the wire loop was monitoredduring the test to insure continued smoldering. The test was terminated once flaming occurred.3.3.3 Cooking IgnitionThe cooking oil fire scenario produced both extendedpyrolyzing and extended flaming combustion. The500 mL of corn oil was poured into a 0.3 m (12 in)diameter aluminum saute pan. A propane burnerprovided approximately 1.5 kW to the underside of thepan, typical of cooking applications. The corn oilpyrolyzed for a period of time, after which a transitionto flaming occurred, consuming the remainder of thecorn oil. Figure 86 shows the heating ignition source.3.4 Test Geometry3.4.1 Manufactured HomeThe manufactured home geometry represented an arrayof residential layouts. The arrangement of themanufactured home was sufficiently generic as to72Figure 86. Heating ignition source withcooking oilrepresent an apartment, condominium, or small ranch house, in addition to a manufacturedhome. The primary partitioning of the 85 m 2 (910 ft 2 ) home consisted of three bedrooms, onefull bathroom, one kitchen/dining area, one living room, and two hallways. Each bedroom also