Dwyer, CDTR-2N4B4-LCD, Series CDTR Carbon Dioxide/RH/Temp Transmitter, 10 kOhms Type 2 NTCNDIR CO2 Sensor, Universal CO2/RH OutputsSeries 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 lower installation time of mounting multiple housings, while lowering material cost at the same time. Even with the three sensors combined into a single unit, replacement cost is not increased due to the pluggable nature of the humidity sensor, which allows it or the temperature to be replaced at a fraction of the cost of a new CO2 transmitter.Like our popular Series CDT Carbon Dioxide Transmitter, a single-beam dualwavelength non-dispersive infrared (NDIR) sensor is used to automatically correct the measurement in both occupied* and unoccupied buildings against light source aging effects. The single-beam dual-wavelength sensor technology provides a higher level of accuracy compared to Automatic Baseline Correction methods which can unintentionally shift the calibration based on CO2 levels and barometric pressure conditions. In order to achieve the best possible accuracy, the Series CDTR also includes digital barometric pressure adjustment and the ability to field-calibrate the sensor. When ordering a duct mount configuration or a wall mount configuration without the display, the Model A- 449 or A-449A remote LCD display can plug into the miniature connector port on the transmitter. The display can be configured to display temperature only, relative humidity only, CO2 only, CO2 and humidity, or CO2 and temperature. Push buttons are standard on all configurations of the transmitters for access to the menu structure, but wall mount configurations can be ordered without the buttons. To prevent tampering, the action of the buttons can be locked out using an internal jumper selection. Menu items that can be accessed via the push buttons include: engineering units, relay output set points, display configuration, transmitter output scaling, ambient barometric pressure, and field calibration of the transmitter.*For buildings occupied 24 hours per day, it is recommended that calibration be verified every 6 to 12 months depending on application.Product ApplicationsOn Demand VentilationApprovalsCE ApprovalRoHS.