Calibrate to other than 420ppm?
anastrophe
Posted: 22.04.2023 02:50
Modified: 21.11.2024 06:06
As we know, CO2 levels are highly variable by location. I live in a moderately populated suburb. I calibrated my two Aranets here. I sent one to my brother, who lives in a well forested mountain area about 100 miles away. When he turned it on it register as low as 360ppm.
How can one truly calibrate to local levels?
I realize that for normal purposes, a hundred ppm difference is immaterial - I'm just curious!
aranet-techsupport
Posted: 24.04.2023 10:12
Modified: 24.04.2023 10:13
Hello anastrophe!
After change of location where CO2 levels are highly different, manual calibration should be performed again. Here you can find instructions on how to do it.
If any other assistance is required, please contact us via support@aranet.com
Aranet Tech Support
anastrophe
Posted: 25.04.2023 23:07
Thank you. I understand how to do that. The problem is that - unless I'm missing something - there is no way to calibrate to the local levels. If the true local level somewhere is 360, then calibrating to a strict 420 overestimates the level. If the true local level somewhere is 600ppm (such as an inner-city area) then after calibration it will be giving an under-representation.
Again - I know these are small differences in the greater scheme of things. It would be cool if one could use a public resource to find what current levels are near where one is, and calibrate to that.
cheers!
aranet-techsupport
Posted: 26.04.2023 09:43
Hello anastrophe,
Thank you for feedback.
Yes, it is true that calibration should be done in environments where value of CO2 is close to 420 ppm for it to be accurate.
Unfortunately, we cannot provide resource for every local area CO2 level as those differ and are affected by multiple factors locally.
Here you can check the global map of CO2 emissions by location, but that will not be completely accurate due to local changes in CO2 levels: https://earth.nullschool.net/#current/chem/surface/level/overlay=co2sc/orthographic=29.16,51.27,791/loc=24.215,57.021
Sorry for any inconvenience.
Aranet Tech Support
rhadorn
Posted: 13.12.2023 08:58
Should it not be possible to enter in the app the value to which to calibrate? I cannot fly to Mauna Loa to calibrate...
aranet-techsupport
Posted: 13.12.2023 09:40
Hi!
That is not currently available but we are evaluating the possibility of this type of feature.
And you do not need to fly anywhere to calibrate, just need to be around 420ppm for Co2 calibration. If the environment is slightly off the 420ppm, then all measurments will be just slightly off too. For normal usage that should not be a big problem.
zerojosh
Posted: 14.08.2024 02:17
Modified: 14.08.2024 02:18
The area I live in is always 460ppm or above, so it will be impossible for me to calibrate to 420ppm. In that scenario, do I need to do mental-math every time I view my monitor to account for +40ppm (not counting the additional +/- accuracy range)?
It would be better if there was an off-set one could enter in the app.tina
Posted: 16.08.2024 09:31
Modified: 16.08.2024 10:08
That is really the problem with manual calibration by the user, it is not so easy to find an environment with 420 ppm. I have tested it multiple times in my local area with brandnew factory calibrated aranet4 and TFA Dostmann and Bresser CO2 devices.
Hardly have I ever seen 420ppm - usually values above in my 150.000 inhabitant city, even if I went to a forrest nearby the city. 400 to 420 ppm I have seen in a mountain area where I went for holidays.
It is kind of dissatisfying for a CO2 device of high theoretical accuracy and after manual calibration just not getting close to the true values anymore.
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