CDTR-2N4E4 is a series CDTR carbon dioxide, relative humidity and temperature transmitters reduce the number of sensors mounted on a wall or in a duct. By combining CO2, RH, and temperature in one device, system integrators are able to reduce installation time while lowering material cost at the same time. Like our popular Series CDT Carbon Dioxide Transmitter, a non-dispersive infrared (NDIR) sensor is used to make the CO2 measurement. In order to achieve the best possible accuracy, the series CDTR also includes digital barometric pressure adjustment. Universal outputs for both carbon dioxide and relative humidity allow users to select the transmitter output to be 4-20mA, 0-5VDC, or 0-10VDC to work with virtually any building management controller. Additionally, passive thermistor or RTD sensor can be ordered for a temperature output.