The Telaire T3032220K24P Industrial CO2 Sensor, Dual Channel, 0 - 20,000 PPM,4 to 20 mA o/p Potted is a Carbon Dioxide (CO2) Sensor designed to meet the specific needs of customers who require measuring CO2 in harsh or difficult environments. Based on a series of modules, the casing offers a number of combinations to meet the needs of range, supply voltage, and output type in various applications. Example applications include incubators, buses, refrigerators, subway stations, and railway carriages.