C02 after recalibration

#1

I have the One Air Quality Sensor DIY kit. Today I flashed v3.1.1 through the browser, and accidentally recalibrated the CO2 sensor when it was ~800ppm inside the room.
Later I read to put it outside when calibrating, so I left it out on the porch for 20 minutes and initiated another calibration. Now its back inside at its usual spot and its showing 1000+ when it should be lower.
Does the calibration take days to complete/adapt? How accurate is it? Would a complete wipe/flash help? What would be the best way to get back to where I was before I calibrated?

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#2

What makes you think it should be less than 1000? My house sits between 1000-1700 nearly all of the time unless I have windows open and fans running.

You did the correct process. After sitting it outside for awhile and then initiating the calibration, it should be reading very close to 400. Once you observe that, bring it inside and it should be accurate.

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#3

A few reasons:

  1. 20-30 minute before recalibration i was at around 800ppm CO2.

  2. looking at my historical data in grafana, this matches up.

  3. For the past 6 months, co2 levels above 1000 only happen when we are cooking, or have people over.

With that said, the sensor seems to have normalized a little bit and now shows prior trends.
I am mot sure if there is auto calibration that happens in the background over time?

#4

If the Automatic calibration had adjusted to a number higher than 400 in your house, then all of the numbers will be off since it calibrated to a false assumption.

I have one device that I’ve disabled ABC and it shows 1027. Another device sitting right next to it has the automatic weekly calibration enabled and it is showing 826, which is 200 lower than the real reading. This is because the lowest the house has gotten in the last week was 600 which is calibrated to assume this is “400” and now will always misreport.

I know there are plans to be able to adjust the calibration period in the AirGradient Dashboard, but I don’t see it looking at the moment.

I run mine with ESPHome firmware and have an option to disable the Automatic Baseline Correction so once every month or two I take them outside and get a new correction.