GMM20W is a new CO2 sensor module from Vaisala that uses a silicon-based CARBOCAP sensor for excellent stability and reliability. The module requires almost no maintenance and is recommended to be calibrated every five years. This combined with its high performance makes GMM20W modules an ideal choice for OEM applications related to ambient CO2 measurement.
The manual introduces the Vaisala GMM20W CO2 module, highlighting its silicon‑based CARBOCAP® sensor technology and its suitability for OEM ambient CO₂ measurement.
It details electrical connections, power‑supply specifications, service and maintenance procedures, full technical specifications, and optional accessories such as relay and LonWorks® interfaces.
| Measuring range | 0…2000 ppm CO₂ (nominal) |
|---|---|
| Accuracy at 20 °C | < ±[1 % FS + 1.5 % of the reading] |
| Repeatability | < +1 % FS |
| Temperature dependence of output | < 0.05 % FS/°C |
| Long‑term stability | < ±5 % / 5 years |
| Response time (0…67 %) | 1 minute |
| Operating temperature | -5 °C … +45 °C |
| Power supply (nominal) | 24 VDC/VAC (18…30 VDC or 20…26 VAC) |
| Power consumption | < 2.5 W |
| Dimensions | 72 × 74 × 19 mm |
| Weight | 56 g |
The recommended calibration interval is five years.
It requires a nominal 24 VDC/VAC supply, with an acceptable range of 18…30 VDC or 20…26 VAC.
The module measures 72 × 74 × 19 mm and weighs 56 g.