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

Time to Alarm Threshold (s)A1300120011001000900800700600PE lowPE midPE highION lowION midION highA B C D E F GAlarm LocationMass Concentration (mg/m 3 )C50403020100Mass conc. (mg/m^3)Number conc. (p/cm^3)0 200 400 600 800 1000 1200 1400Time (s)1 10 68 10 56 10 54 10 52 10 50Number Concentration (particles/cm 3 )Air Temperature ( o C)B35302520temperaturerelative humidity0 200 400 600 800 1000 1200 1400Time (s)504540353025Relative Humidity (%)Ion Chamber (volts)D65.554.54Chamber 1Chamber 2Number00 200 400 600 800 1000 1200 1400Time (s)1 10 68 10 56 10 54 10 52 10 5Number Concentration (particles/cm 3 )Figure 181. Smoldering wood blocks - eight beech wood blocks on an electric hotplate, locatedon the living room floor at the chair burn location. Fan was on. Power to hotplate on at t=06.4.3 Polyurethane Foam SmolderBlocks of polyurethane foam, (approximately 8 cm x 8 cm x 10 cm) were removed from a chaircushion of the same type used in the smoldering chair fire scenario in the Home Smoke Alarmtests. A single block was used in each smolder test. A slit was made in the foam at the center ofthe 10 cm high block, and a nichrome heating wire (similar to the one used to ignite the chairsfor the smoldering fire tests) was inserted. Electric power was applied to the wire to cause thefoam block to smolder in the same manner as the fire tests discussed in section 3.3.2.Smoldering was allowed to proceed for approximately 15 min. The test was repeated three timeswith the floor fan off and once with the floor fan on.201