Color Coded Levels
Green
The green color represents a healthy environment with low carbon dioxide. Consistent green readings mean the space is well ventilated and safe. The carbon dioxide levels can also be green when there are few people. The text will be green if the carbon dioxide levels are less than 800 ppm.
Orange
The orange color represents a partially safe environment with medium levels of carbon dioxide. It is recommended to improve ventilation if there is steady orange readings. The text will be orange if the carbon dioxide levels are between 800 ppm and 1400 ppm.
Red
The red color represents an unhealthy environment that should definitely improve its ventilation. Head over to the Improving Ventilation section if you see persistent red readings. Dr. Bhagat from Cambridge University warns that any reading above 1500 ppm is extremely unhealthy for humans.
Beware of high fluctuations of CO2 levels!
Sometimes there may be dangerously high levels of carbon dioxide in the air. In the image on the right the CO2 level was 7092 ppm. However, this is because of people breathing heavily near the sensor. The carbon dioxide exhaled by people can effect the CO2 readings the sensor picks up. Please ensure that no one is extremely close (6 inches and below) to the sensor. This can heavily influence the sensor's readings. Usually, if someone breathes on the sensor, the readings will go down after a few minutes. Do not worry if there are suddenly high carbon dioxide levels. However, if there is consistent bad carbon dioxide levels, then please caution, because it may be a dangerous area.