The PPM-7001 is a very accurate CO2 PPM monitor. The PPM-7001 CO2 Monitor is a stand-alone device that detects carbon dioxide and temperature levels. Large LCD displays CO2 level, temperature and ventilation rates in standard or metric units. It employs dual-beam, infrared gas sensor technology and operates with batteries or AC power adapter (included). It can be used with Data Loggers to record time and date stamped, CO2 (carbon dioxide) levels as well as temperature data for graphing and detailed analysis.