Why do CO2 monitors display different readings in the same environment?
There are a few considerations.
The specification for the sensor is +/- 50 ppm and +/- 5% of reading. So in the worst case, a concentration of 418 (typical fresh air) could read between 348 and 488. These are not aboratory instruments, thay are a rough guide only.
The small form factor of the AirSpot makes it likely your breath will fall on the device when you're holding or wearing it. This will result in higher readings than the average CO2 in the room. To overcome this for testing purposes I use a glass dish to enclose all my reference devices, like this:
It is coincidental that one of the AirSpots matches one of the Aranets and the other matches the Inkbird. Note also that in one example the Aranets disagree by 5%.
Finally, I would not be too concerned about the exact reading.
Whether CO2 is 700 or 800 ppm doesn't mean much.
What is important is that big numbers (in the thousands) are a warning of poor ventilation.
Smaller numbers that keep climbing are also an alarm bell, for example if it's going up 100 ppm every 3 minutes you know the ventilation is not enough to replace exhaled air with fresh air. I'm more concerned about trends than absolute numbers.
The specification for the sensor is +/- 50 ppm and +/- 5% of reading. So in the worst case, a concentration of 418 (typical fresh air) could read between 348 and 488. These are not aboratory instruments, thay are a rough guide only.
The small form factor of the AirSpot makes it likely your breath will fall on the device when you're holding or wearing it. This will result in higher readings than the average CO2 in the room. To overcome this for testing purposes I use a glass dish to enclose all my reference devices, like this:
It is coincidental that one of the AirSpots matches one of the Aranets and the other matches the Inkbird. Note also that in one example the Aranets disagree by 5%.
Finally, I would not be too concerned about the exact reading.
Whether CO2 is 700 or 800 ppm doesn't mean much.
What is important is that big numbers (in the thousands) are a warning of poor ventilation.
Smaller numbers that keep climbing are also an alarm bell, for example if it's going up 100 ppm every 3 minutes you know the ventilation is not enough to replace exhaled air with fresh air. I'm more concerned about trends than absolute numbers.
For more information on CO2 monitoring why not check out our 'CO2 monitors' solutions link: https://airspothealth.com/a/blog/category/co2-monitors
