CDSN - CO2 Room Sensor. 0-2000ppm, 0-10VdcThe Model CDSN Carbon Dioxide Transmitter accurately monitors the CO2 concentration and temperature in schools, office buildings, and other indoor environments to help achieve LEED certification and energy savings. In order to achieve a higher level of accuracy, the Model CDSN includes digital barometric pressure adjustment. The CO2 universal output allows users to select the transmitter output to be 4 20 mA, 0 5 VDC, or 0 10 VDC to work with