Compact CO2 monitor with alarm for many applications in air quality monitoring, in greenhouses, in energy management and in research and teaching. The ECO 420-20 is an ideal measuring and warning device for moderate but non-hazardous concentrations - it is not a substitute for personal protective equipment that must be used in areas with a potentially hazardous atmosphere. The CO2 is measured by a high-quality non-dispersive infrared sensor (NDIR) via an opening on the device head. Simultaneous indication of the time-weighted average exposure over 8 hours (TWA) or 15 minutes (STEL).ApplicationsMonitoring CO2 for occupations exposed to increased exposure: CO2 dosemeter over 8 hours average TWA. Very mobile because of belt clip and carrying strap and 24 h battery life!Air hygiene monitoring with two adjustable alarm thresholds. The first can be used as an alarm for ventilation; the device beeps and flashes in case of an alarm. For forced ventilation the beep can be suppressed for 5 minut