HD37 - CO2 and Temperature active transmitters. 4-20mA or 0-10VDC output. Alarmlevel for CO2 levels. Wallmounted or mounted directly in ducts for HVAC.

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Product Information

The HD37BT... and HD37VBT... series transmitters are used mainly in air quality control by measuring CO2 (Carbon Dioxide) in the ventilation systems. This allows you to vary the number of air change per hour according to ASHRAE and
IMC norms. The purpose is twofold: to have a good air quality in the presence of people and to save energy, increasing or decreasing parts of air per hour, depending on the air quality set.
The use is for environments where there is overcrowding of people, discontinuous crowding, cafeterias, auditoriums, schools, hospitals, greenhouses, livestock breeding, etc.
The HD377BT... and HD37V7BT... models measure, in addition to CO2, also the temperature. The analog outputs, current 4...20mA or voltage 0...10Vdc, should be specified when ordering. All transmitters have an alarm digital output suitable to control, for example, an external relay coil.

Code selections of the desired model:

Samenstellen typenummer HD37, CO2 en Temperatuur transmitter


Uitvoering TV, HD37 transmitters          

                            TV serie           

      HD37, TO serie. Directe montage in luchtkanaal.

                                 TO serie

Transmitter met tube aansluiting. HD37

                                TC serie

Electrical schematics:

Elektrisch schema HD37

Mounting possibilities TO series:

Montage HD37 series



Following codes can be delivered:

HD37.36 , HD37.37 , HD37BTV , HD37BTV.1 , HD37BTO.1 , HD37BTO.11 , HD37BTO.2 , HD37BTO.21 , HD37BTC , HD37BTC.1 , HD37VBTV , HD37VBTV.1 , HD37VBTO.1 , HD37VBTO.11 , HD37VBTO.2 , HD37VBTO.21 , HD37VBTC , HD37VBTC.1 , HD377BTV , HD377BTV.1 , HD377BTO.1 , HD377BTO.11 , HD377BTO.2 , HD377BTO.21 , HD37V7BTV , HD37V7BTV.1 , HD37V7BTO.1 , HD37V7BTO.11 , HD37V7BTO.2 , HD37V7BTO.21 , HD3719 , HD3721


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Product type

Measurement Principles