FIREBOY-XINTEX Battery Operated Marine Carbon Monoxide Detector How The Xintex CMD6-M CO Alarm Works: The Firebox Xintex CMD6-M Marine 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 as expressed as a percentage. The human body absorbs CO easier than oxygen and COHb is the ratio absorbed carbon monoxide to oxygen in bloodstream. The CMD6-M alarm calculates the COHb as function of time and determines the appropriate alarm response. Recommended Carbon Monoxide Detector Installations: A carbon monoxide detector should be installed in each accommodation space. Small crafts or RVs with an open design may require only one detector for adequate protection if two or more sleeping areas or spaces are partitioned and one detector should be installed in each of the spaces. Alarm with NEW Sensor Technology Features: