Abstract: Various arrangements for operating a hazard detector are presented. A smoke concentration may be measured using a sensor of the hazard detector. A carbon dioxide concentration may be measured using a carbon dioxide sensor of the hazard detector. The measured smoke concentration may be analyzed in combination with the measured carbon dioxide concentration to determine whether a heads-up alert or warning alarm is to be output. The heads-up alert or the warning alarm may be output based on analyzing the measured smoke concentration in combination with the measured carbon dioxide concentration.

Abstract: Various arrangements for operating a hazard detector are presented. A smoke concentration may be measured using a sensor of the hazard detector. A carbon dioxide concentration may be measured using a carbon dioxide sensor of the hazard detector. The measured smoke concentration may be analyzed in combination with the measured carbon dioxide concentration to determine whether a heads-up alert or warning alarm is to be output. The heads-up alert or the warning alarm may be output based on analyzing the measured smoke concentration in combination with the measured carbon dioxide concentration.

Abstract: Various arrangements for operating a smoke detector are presented. A voltage output by a light sensor of the smoke detector may be measured. A carbon monoxide concentration using a carbon monoxide sensor of the smoke detector may be determined. A smoke concentration using the voltage signal may also be determined. A smoke concentration warning threshold based on the determined carbon monoxide concentration may be determined. The determined smoke concentration may be compared to the smoke concentration warning threshold. A warning alarm may be generated in response to comparing the determined smoke concentration to the smoke concentration warning threshold.

Abstract: A smoke detector includes an illuminator, a light sensor, a memory, and a microprocessor. The illuminator is configured to emit a first electromagnetic signal having a first center wavelength and a second electromagnetic signal having a second center wavelength. The light sensor is configured to generate (a) a first clean-air voltage in response to receiving the first electromagnetic signal and (b) a second clean-air voltage in response to receiving the second electromagnetic signal. The memory stores non-transitory computer-readable instructions. The microprocessor is adapted to execute the instructions to: (i) determine a first signal drift value from the first clean-air voltage and a first reference voltage, (ii) determine a second signal drift value from the second clean-air voltage and a second reference voltage, and (iii) determine the operational state from both the first signal drift value and the second signal drift value.

Abstract: Various arrangements for operating a smoke detector are presented. A voltage output by a light sensor of the smoke detector may be measured. A carbon monoxide concentration using a carbon monoxide sensor of the smoke detector may be determined. A smoke concentration using the voltage signal may also be determined. A smoke concentration warning threshold based on the determined carbon monoxide concentration may be determined. The determined smoke concentration may be compared to the smoke concentration warning threshold. A warning alarm may be generated in response to comparing the determined smoke concentration to the smoke concentration warning threshold.

Abstract: A method of operating a smoke detector comprising an illuminator, a light sensor, and a carbon monoxide sensor includes the step of measuring a voltage signal in response to an electromagnetic signal emitted by the illuminator. The method comprises the step of determining a smoke concentration using the voltage signal, and the step of determining a carbon monoxide concentration using the carbon monoxide sensor. The method includes comparing the smoke concentration and the carbon monoxide concentration to a warning zone criteria, and the step of calculating a rate of increase of at least one of smoke and carbon dioxide based on a determination that the warning zone criteria is unmet. The method comprises generating an alarm in response to a determination of a warning condition.

Abstract: A smoke detector includes an illuminator, a light sensor, a memory, and a microprocessor. The illuminator is configured to emit a first electromagnetic signal having a first center wavelength and a second electromagnetic signal having a second center wavelength. The light sensor is configured to generate (a) a first clean-air voltage in response to receiving the first electromagnetic signal and (b) a second clean-air voltage in response to receiving the second electromagnetic signal. The memory stores non-transitory computer-readable instructions. The microprocessor is adapted to execute the instructions to: (i) determine a first signal drift value from the first clean-air voltage and a first reference voltage, (ii) determine a second signal drift value from the second clean-air voltage and a second reference voltage, and (iii) determine the operational state from both the first signal drift value and the second signal drift value.

Abstract: A method for distinguishing between an alarm condition and a nuisance condition in a smoke detector. The smoke detector comprises an illuminator and a light sensor. The method includes measuring a voltage signal in response to an electromagnetic signal emitted by the illuminator, and comparing the voltage signal to an alarm threshold. A rate of change of the voltage signal is determined in response to the comparison of the voltage signal and the alarm threshold. A first frequency component of a first portion of the voltage signal and a second frequency component of a second portion of the voltage signal is determined. The first frequency component and the second frequency component are compared to distinguish between the alarm condition and the nuisance condition. An indication of the alarm condition and the nuisance condition is respectively generated upon an identification of the alarm condition and the nuisance condition.