Combined Carbon Dioxide, Temperature, and Humidity Transmitters


Combined Carbon Dioxide, Temperature, and Humidity Transmitters

Application of GMW90


Combined Carbon Dioxide, Temperature, and Humidity Transmitters


  • Measured parameters: carbon dioxide, temperature, and humidity (optional)
  • Superior long-term stability with the next generation Vaisala CARBOCAP® sensor
  • Accurate temperature and humidity measurements in a three-parameter instrument due to the low-power microglow infrared source
  • Quick and easy installation and maintenance
  • Calibrated, user-exchangeable modules for carbon dioxide, temperature and humidity
  • Traceable calibration (certification included)
  • Digital communication with BACnet/Modbus
  • Decorative cover available to match your building’s interior design

The Vaisala GMW90 Series CARBOCAP® Carbon Dioxide, Temperature, and Humidity Transmitters are based on new measurement technology for even more reliable and stable readings yet than used to. These wall-mounted transmitters are easy to install and have very low maintenance requirements.

Designed for demand controlled ventilation, these transmitters measure carbon dioxide and temperature, with the option for humidity measurements. The instruments come with a calibration certificate that meets traceability and compliance requirements.

Reliability from Unique Measurement Technology

The GMW90 Series Transmitters use advanced Micro-Electro-Mechanical System (MEMS) technology for measuring carbon dioxide. The CARBOCAP® carbon dioxide sensor's continuous reference measurement enables reliable and accurate readings and outstanding long-term stability also in buildings with round-the-clock occupancy.

The new generation CARBOCAP® sensor no longer uses an incandescent light bulb, which limits sensor lifetime. This unique sensor consumes very little power compared to other sensors on the market. As a result, instrument self-heating is low and humidity and temperature can be measured correctly.

Convenient Installation

GMW90 Series Transmitters have been designed for quick and easy installation and maintenance. Every model includes a display for easy startup and convenient maintenance.

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. Dip switches make it quick and easy to configure the transmitters.

Easy Calibration

Regular instrument maintenance guarantees a long product lifetime. Calibration is easiest done with 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 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.

Types of Carbon Dioxide Products - Fixed Installations