Amprobe CO2-200 Wall-Mounted CO2 Meter<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Wall-mounted digital meter measures ambient level of carbon dioxide (CO2) to monitor indoor air quality and performance of heating， ventilation， and air-conditioning (HVAC) systems</li><li>Displays current CO2 levels， long-term average CO2 levels measured over an 8-hour period， and short-term average CO2 levels measured over a 15-minute period</li><li>Alarm notifies operator when CO2 levels reach or exceed a preset threshold</li><li>When connected to a building's HVAC system， the meter's built-in relay activates the HVAC system if CO2 levels reach or exceed the alarm's upper-limit threshold</li><li>Liquid crystal display (LCD) shows ambient CO2 levels， as well as air， wet bulb， or dew point temperature and humidity</li><li>CO2 measurement up to 9999 ppm， temperature， relative humidity， dew point and wet bulb</li><li>High performance low drift sensor designed with NDIR (non-dispersive infrared) waveguide technology with automatic background calibration</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41pjU%2Bj1oPL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41lQQPSElrL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/41o26iILq2L.jpg" noproxy>