Patent attributes
A fire detector and method of using it generate a fire alarm through use of a smoke detector and a carbon monoxide detector once the smoke detector detects a threshold level of light obscuration for greater than a first pre-selected time period or a reduced threshold level of light obscuration for greater than a second pre-selected time period or the CO detector detects a rate of increase in CO concentration which exceeds a first preselected CO rate for a third pre-selected time period and the smoke detector detects the reduced threshold level of light obscuration or the rate of increase in CO concentration exceeds a second preselected CO rate for a fourth pre-selected time period. The fire detector and method can also use a carbon dioxide detector and generate the fire alarm when either a rate is of increase in concentration of CO2 exceeds a first CO2 predetermined rate for a fifth pre-selected time period and the smoke detector detects a reduced threshold level of light obscuration or the rate of increase in concentration of CO2 exceeds a second CO2 predetermined rate for a sixth pre-selected time period.
