Microprocessor-based combination smoke and carbon monoxide detector having intelligent hush feature

A hazardous condition detector (10), comprises a carbon monoxide detector circuit (16) positioned to sense atmospheric conditions. The carbon monoxide detector circuit (16) is operable to produce an output indicative of the amount of carbon monoxide detected thereby. The detector (10) also has a smoke chamber (14) positioned to sense atmospheric conditions. The smoke chamber (14) is operable to generate an output indicative of an amount of smoke sensed therein. The detector (10) also has an alarm circuit (20), and a microcontroller (12) coupled to receive the output of the carbon monoxide detector circuit (16) and the output of the smoke chamber (14). The microcontroller (12) is operably coupled to the alarm circuit (20). The microcontroller (12) places the detector (10) in a smoke alarm mode commanding the alarm circuit (20) to generate an alarm when the output of the smoke chamber (14) descends below a smoke threshold stored therein. The microcontroller (12) places the detector (10) in a carbon monoxide alarm mode when an accumulation of the output of the carbon monoxide detector circuit (16) exceeds an accumulation threshold stored within the microcontroller.