CO2, Temperature and Humidity Transmitter Series GMW90

for green building projects

5 year warranty HVAC devices

The wall-mounted Vaisala GMW90 Series CARBOCAP® Carbon Dioxide, Temperature and Humidity Transmitters are especially suited for green building projects and demand controlled ventilation. The devices measure carbon dioxide and temperature and have an option for an additional humidity measurement. 

Intelligent measurement modules

The instruments come with a calibration certificate that meets traceability and compliance requirements. Traceability is easily maintained with field-exchangeable intelligent measurement modules.

The transmitter can be blended into the interior design of the space where it is installed using the optional decorative cover. 5-year warranty is valid for instruments purchased in 2021 and beyond.

View all our instruments for HVAC applications.

Click here to download bid specs for USA.


  • Measured parameters: carbon dioxide, temperature, and humidity (optional)
  • Superior long-term stability with the next generation Vaisala CARBOCAP sensor
  • Accurate temperature and humidity measurements due to the low-power microglow infrared source
  • Quick and easy installation and maintenance
  • Calibrated, user-exchangeable measurement modules
  • 3-point traceable CO2 calibration (certification included)
  • Both analog outputs and fieldbus communication (Modbus RTU)
  • Optional decorative cover blends the transmitter into your interior design

Key benefits

Easy installation

The GMW90 Series Transmitters have been designed for quick and easy installation. Every model includes a display for easy startup. To protect the sensor from dust and dirt during construction and installation, the units can be cabled with back-plate only. Electronics can be snapped on later at an appropriate phase in the construction project. This saves installation time in the project.

Convenient calibration

Regular instrument maintenance guarantees a long product lifetime although the transmitter’s inspection interval is five years. Calibration is easiest using the exchangeable measurement modules. Sensor traceability and measurement quality is easily maintained by snapping on a new module calibrated at Vaisala factory. The instrument can also be calibrated using a hand-held meter or reference gas CO2 bottle. The service interfaces are easy to reach by simply sliding the cover down. The closed cover keeps the measurement environment stable during calibration and ensures a top-quality final result.

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