CO₂ measurement
Due to the accumulation of gases from adhesives, cleaning products, smoke, dust, dust mites and mold in a confined space, your indoor air can rapidly become unhealthy.
The CO₂ is produced by human activities and can rapidly concentrate in confined spaces such as a living room, bed room, office...
As CO₂ level rises, so does the concentration of unhealthy components of indoor air. CO₂ level is therefore a good air quality indicator.
The CO₂ level is measured by the station's indoor module.
CO₂ indicator
For a quick reading of the CO₂ level, the following color code is used:
- Green = good
- Yellow = Could be improved
- Red = Room should be ventilated.
This indicator is represented by a colorful indicator.
For a direct reading, the light on the indoor module uses the same color code: if you touch the top of the indoor module, it briefly lights up and gives you an indication of the current CO₂ level in the room.
Units
CO₂ is measured in ppm (parts per million), meaning the number of CO₂ molecules among one million air molecules. Usual indoor CO₂ levels vary between 400 and 5000 ppm.
Typical ppm values
- Outdoor, CO₂ level is always around 400 ppm.
- In an appropriately ventilated room, the CO₂ level should remain below 1000 ppm for the upmost comfort.In a closed room such as a meeting room with several people or a small bedroom at night, CO₂ can easily go past 1000 ppm.
Consequences
CO₂ is not dangerous when kept within such values.
Nevertheless, when it rises over 1000 ppm, it is an indication that indoor air has not been renewed for a long time.
If this happens, ventilating the room is a simple and effective action.
Over 2000 ppm CO₂ can also cause sleepiness and slight headaches.
CO₂ Alerts
When the CO₂ level rises above 1000 ppm, a notification is sent to your smartphone and the indoor module briefly lights up yellow. When the CO₂ level goes above 2000 ppm, a second alert is sent to your smartphone and the indoor module briefly lights up red.
How does the Netatmo station measure the CO₂ concentration?
The sensor measures CO₂ using an optical process: the Station is embedded with a light bulb and an infrared receiver. Light is emitted from the bulb and partially absorbed by the CO₂ contained in the ambient air. The higher the CO₂ level, the more the light is absorbed. The infrared receiver then measures the amount of light received and from there it deducts the CO₂ level. This method works regardless of the ambient light.
Calibration
To ensure the accuracy of your CO₂ measurements, the Netatmo Weather Station automatically and regularly recalibrates its CO₂ sensor. This calibration is performed assuming that the CO₂ level surrounding the station lowers to 400 ppm at least once a week. To achieve a precise calibration, make sure to ventilate the room for a period of time long enough to entirely renew the air.
Manual CO₂ calibration
If the Netatmo station fells on the ground or goes under similar shocks, it may be necessary to perform a manual calibration of the CO₂ sensor. For this purpose please visit the CO2 Calibration tab of your station in Settings > Home management > Room of the product > Product concerned > CO₂. Once the manual CO₂ calibration started, please don't unplug the station for at least 6 hours, to let it calibrate. If the station did not go under excessive shock manual CO₂ calibration should not be needed.
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