Dwyer CDTV-2N4B4 Carbon Dioxide Transmitter is a highly accurate sensor for determining carbon dioxide levels. It has a temperature range of 32 to 122°F and an accuracy of ±40 ppm ±3% of reading. It operates on a power supply of 16 to 35 VDC / 19 to 28 VAC and has a response time of 2 minutes for a 99% step change in CO2 levels. With a range of 0 to 2000 or 0 to 5000 ppm (depending on the model), the transmitter is suitable for measuring VOCs as well. It supports various output options such as current and voltage, and has an enclosure rating of NEMA 4X (IP66) for housing only in duct mount configuration. The CO2 sensor is a single-beam, dual-wavelength NDIR design, while the VOC sensor uses a MEMS metal oxide semiconductor. The transmitter consumes an average of 2 watts of power and has a peak power consumption of 3.75 watts. It has a non-linearity of 16 ppm and a temperature dependence of ±8 ppm / °C at 1100 ppm. The pressure dependence of CO2 readings is 0.13% of the reading per mm of Hg. It can operate in a velocity range of 0-4000 FPM (20.32 m/s).