CDT2000 Duct

CO2 transmitters with temperature output for duct

CDT2000 Duct combines CO2 and temperature measurements in one device installed in air ventilation duct. Illuminated display ensures easy readability also from a distance. The CDT2000 Duct has a screwless lid and an easily adjustable mounting flange that make the installation of the device easy.


The CDT2000 Duct series transmitters calibrate themselves automatically using ABC logicTM. The ABC logicTM requires that the space in which the transmitter is used needs to to be unoccupied for four hours per day so that the indoor CO2 concentration drops to the outside level. CDT2000-DC Duct is a dual channel model with a measuring channel and a reference channel that makes a continuous comparison and the necessary adjustment accordingly. CDT2000-DC Duct is also suitable for buildings that are continuously occupied.


CDT2000 Duct series devices include:

• Separate output for each measurement parameter (CO2 and T)

• Offset feature enabling field calibration for each measurement parameter (CO2, T)

• Mounting flange


CDT2000 Duct series device options offer:

• Clear backlit display

• Modbus RTU interface

• 4-20 mA proportional output

Technical details

Accuracy: CO2: ±40 ppm + 3 % of reading, DC model: 75 ppm or 10 % of reading (whichever is greater)
Temperature: <0.5 °C
Measurement elements: NTC10k temperature sensor, Non Dispersive Infrared (NDIR) CO2 sensor
Measuring units: ppm, °C
Calibration: Automatic self-calibration, ABC LogicTM or continuous comparison (DC)
Supply voltage: 24 VDC/VAC ±10 %
Output signal 1: 0/2…5/10 V (linear to CO2)
Output signal 2: 0/2…5/10 V (linear to Temp)
Optional output signal 3: 4...20 mA (linear to CO2) (A model)
Optional output signal 4: 4...20 mA (linear to Temp) (A model)
Operating temperature: 0...+50 °C
Protection standard: IP54

CDT2000 Duct

CDT2000 Duct-D


Product series

Carbon dioxide transmitter, analog outputs
Carbon dioxide transmitter, Modbus communication


ABC logic™, Automatic Background Calibration
Dual channel, for continuously occupied space


Duct mount


Voltage output
Voltage and current output


With display
Without display

Other Carbon dioxide transmitters: