The FIREBOY-XINTEX CMD5-M CO alarm uses a sensor operating with a microprocessor to measure Carbon Monoxide (CO) levels. Using a Time Weighted Average” (TWA) process, it monitors CO concentration, temperature and time to calculate levels of Carboxyhemoglobin (COHb). COHb is the degree to which the oxygen carrying capacity of the blood is impeded by the union of carbon monoxide to the hemoglobin and is expressed as a percentage. The human body absorbs CO easier than oxygen and COHb is the ratio of absorbed carbon monoxide to oxygen in the bloodstream. The CMD5-M alarm calculates this COHb as a function of time and determines the appropriate alarm response.Electrochemical sensorImmediate and stable sensing reduces false alarmsSealed lithium-ion battery requires no power wiringConformal coated circuit board for added protection