Erratic readings prior and post calibration

guest

Posted: 03.09.2023 02:53

Modified: 01.05.2024 01:55

My 1 month old aranet4 was reading between 480 and 560ppm when outside when nullschool readings were 427ppm the https://earth.nullschool.net/#current/chem/surface/level/overlay=co2sc/equirectangular=-208.00,-32.05,2340/loc=150.916,-34.312

I recalibrated outside and the outdoor reading dropped to 407. Yesterday I had the Aranet4 inside with windows open and the reading dropped to 373ppm - with the lowest reading reaching 355! What should I do about this? Could it be faulty?

Thanks

Michael
aranet-techsupport

Posted: 04.09.2023 08:38

Hi.
As with any sensor, the aranet Co2 sensor is not perfect and the shown number is not the true value of the Co2 concentration. Check the datasheet for the sensors accuracy:
https://cdn.bfldr.com/FS48XT6B/at/k9b9wjnv8f455crkp7846j/Aranet4_datasheet_v25_WEB.pdf
As you can see in the datasheet, the true value is somewhere in the "shown value" +/- 30ppm,
Also the Co2 concentration varies during the day, depending on traffic and other Co2 emitters around your home. So keep in mind that those can also effect the readings and the nullschool map is just the average around that area, your locations Co2 may vary.
You can try doing another manual calibration by following the instructions here:
https://forum.aranet.com/all-about-aranet4/how-can-i-calibrate-my-aranet4/
If after reading this post and calibrating your aranet4, you still aren't convinced that it is not faulty, then you can RMA the device.
emwolf

Posted: 10.09.2023 07:22

Thanks will try another calibration. It dropped to 390 today!
emwolf

Posted: 10.09.2023 07:23

PS could you pleaae link my original post to my profile? Not sure why it shows as guest?

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