Room Sensor for CO₂, Temperature and Relative Humidity

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  • CO₂
  • Temperature
  • Humidity


The CDS201 is optimised for demand controlled ventilation and building automation in residential and commercial applications. The versatile room sensor combines CO2, temperature (T) and relative humidity (RH) measurement in one device with modern design and state-of-the-art technology. The elegant enclosure is available in two sizes (EU and US format) and features an optional display.

  • CDS201 CO₂, temperature and humidity sensor with display - EU format

  • CDS201 CO₂, temperature and humidity sensor - EU format

  • CDS201 CO₂, temperature and humidity sensor with display - US format

  • CDS201 CO₂, temperature and humidity sensor - US format

    Outstanding Measurement Performance
    The CO2 measurement of the CDS201 relies on the pollution-resistant E+E dual wavelength NDIR technology. This measuring principle automatically compensates for ageing effects and ensures excellent long-term stability. The multiple point CO2 and temperature adjustment procedure leads to excellent CO2 measurement accuracy over the entire temperature working range.

    The E+E proprietary sensor coating protects the RH/T sensing element from contamination and corrosive deposits. This improves the measuring performance and service life of the sensing element in dusty or dirty environments.

    Outputs and Digital Interface
    The CDS201 room sensor features analogue outputs or RS485 interface with Modbus RTU or BACnet MS/TP protocol. In the digital version, the CDS201 also calculates the dew point temperature (Td). The measured values can also be read locally on the optional graphic display.

    The version with RS485 interface can be set up and configured via PC with the free PCS10 Product Configuration Software and an optional configuration adapter.

    Installation-friendly Enclosure
    The enclosure of the CDS201 facilitates fast and thus cost-saving installation. The back cover with the push-in spring terminals can be mounted and wired without the front cover. This means that the electronics, which are accommodated in the front cover, are not exposed to construction site pollution. Before commissioning, the active part can be simply snapped onto the back cover. Besides, the electronics part can be replaced without tools within seconds.

    Typical Applications

    • Demand controlled ventilation
    • Heating, ventilation and air conditioning
    • Building automation

    Key Features

    • CO2, T, RH measurement with a single device
    • Calculation of dew point temperature Td (CDS201 with RS485)
    • Pollution-resistant CO2 measuring principle
    • RH/T sensing element protected by E+E proprietary coating
    • High accuracy due to multiple point CO2 and T adjustment
    • Modbus RTU, BACnet MS/TP or analogue outputs
    • Large graphic display (optional)
    • Snap-on enclosure for time-saving installation
    • EU and US enclosure format
    • Easy configuration
    CDS201 features

    Technical data

    Measuring range - CO₂
    0...2 000 ppm
    0...5 000 ppm
    Accuracy - CO₂
    < ±(60 ppm +2 % of measured value)
    < ±(60 ppm +3 % of measured value)
    Measuring range - Humidity
    0...100 % RH, non-condensing

    Accuracy - Humidity
    ±(2.8 + 0.003 * mv) % RH (at 0...80 % RH)
    ±4.1 % RH (at >80...100 %RH)
    Measuring range - Temperature
    -30...+60 °C (-22...+140 °F)

    Accuracy - Temperature
    ±0.35 °C (±0.63 °F), voltage output / RS485
    ±0.7 °C (±1.26 °F), current output
    Output analogue
    0-10 V or 4-20 mA
    Output digital
    RS485 (Modbus RTU or BACnet MS/TP)
    Power supply
    15-35 V DC or 24 V AC ±20 %

    Calibrating your limits

    Your products and services can only be as precise as the tools you use to measure them. With more than 20 years of experience, the calibration team of E+E Elektronik focuses on providing a reliable service without any unnecessary delays or bias.

    Discover the value of working with an expert in calibration that prioritizes

    • accuracy,
    • fastness and
    • reliability

    Learn more

    Related products



    Downloads CDS201


    Transmitter with "two-wire" technology receive the power from the process, and the signal is carried on return wire (closed current loop). With "three-wires" technology the power supply is separate from current output: 2 wires are the power supply and the third carries the signal.

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