US Patent 11756400 Self-testing hazard sensing device

Devices, methods, and systems for a self-testing hazard sensing device are described herein. One device includes a sensor, a wire dipped in a material, a controller configured to provide a current to the wire to heat the material and generate aerosol and/or carbon monoxide, and an airflow generator configured to provide the aerosol and/or carbon monoxide to the sensor. The controller configured to determine whether the self-testing hazard sensing device is functioning properly using the aerosol and/or carbon monoxide provided to the sensor.