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Modbus CO2 Sensors | HDH-M-N HDH-M-N Modbus CO2/Temp Transmitters, Display

HDH room transmitters measure CO2 content and temperature in wide range of applications. The transmitters use the unique ABCLogic™ measurement technology that automatically resets the zero point (calibrates the CO2 detector). The HDH-M transmitters come with integrated Modbus RTU RS-485 communication interface allowing savings in the BMS system IO-requirements and providing accurate measurements.

The transmitters have temperature measurement outputs as standard, and humidity measurement can be offered as an option. Industry standard 0..10Vdc outputs guarantee integration to most applications. The transmitters are available with (-N models) or without display. These CO2 transmitters can also accommodate built-in control making them most advanced solution for accurate ventilation control. The control output and modes are configured using ML-SER configuration tool.

RH-models have also relative humidity measurement. The RH-models have additional 0..10Vdc output that relates to the 0..100% rH humidity measurement. The humidity measurement is also available over Modbus.

ABCLogic is a result of over 10 years R&D for the CO2 measurement. ABCLogic measures the background CO2 level and uses the advanced statistical analysis to correct the readings automatically, removing the need for expensive calibration.

Required Tools

ML-SER configuration tool is required to alter the default Modbus address and baud rate.

Modbus CO2 Sensor Diagram  
Power Supply: 24 Vac/dc +15/-30%, <0.5A
CO2 Measurement Range: CO2: 0..2000ppm
Temperature: 0..+50°C
Accuracy: CO2: +/-40pp +3% of measurement
Temperature: +/-0.5°C
Outputs: 4 x 0..10Vdc < 2mA
Communication Interface:

Modbus RTU RS-485

Protection Class: IP20
Dimensions: W87 x H86 x D32 mm