AirGradient Forum

Calibration of AirGradient One PM2.5 readings

#1

Just got an AirGradient One (AG1) indoor air quality monitor. Like many before me have posted the PM2.5 readings were pegged at 0 (zero) for long periods. Figured out one way to calibrate the PM2.5 readings so the AG1 would provide PM2.5 information at the low end of the scale. The calibrated values may or may not be accurate, but now they roughly agree with my reference monitor and the AirVisual app readings in my location.

First AG1 setup was a problem – turning on the AG1 leads nowhere – and instructions on the AirGradient website are convoluted. Eventually I found instructions for connecting to WiFi and came to realize that despite AirGradient’s claim that the AG1 was completely “local” it was necessary to phone home to AirGradient to even start the AG1. The password: cleanair was well hidden. After a forced software update the AG1 screen was showing some numbers.

Next I added the AG1 to Home Assistant (HA). Now the AG1 PM2.5 readings in HA were pegged at 0 (zero) and did not match the reference values.

Calibration Method Used:

(1) Create an account with AirGradient. (The AG1 is not a local device.)

(2) Using Home Assistant set Post data to AirGradient to ON (not local).

(3) Using Home Assistant set Configuration to CLOUD (not local).

(3) Log in to the AirGradient site and setup the AG1 on the AirGradient Dashboard (not local).

(4) Under General Settings – turn on Advanced Configuration.

(5) On the AirGradient Dashboard find the vertical 3 dots under Admin at the right side of the list of values. Go to Advanced Settings.

(6) Having previously taken the AG1 apart and taken a picture of the model of the Plantower particle sensor (the blue box) use the Plantower particle sensor model number to select the correct Calibration Formula for PM2.5. I also applied the EPA Formula.

(7) Confirm that the AirGradient display, the AirGradient Dashboard and Home Assistant report the same readings for PM2.5 and all the other sensors.

(8) Using Home Assistant you can now set Configuration to LOCAL and set Post data to AirGradient to OFF, if you want.

Take-away (1) For calibration the AG1 must be connected to the AirGradient Dashboard and not controlled by Home Assistant.

Take-away (2) AirGradient monitors are NOT local devices, they must be connected to AirGradient to start operation, for calibration and for software update. But ongoing data does not need to be sent continuously to AirGradient.

#2

It should not be required to connect to AirGradient servers to start operation, as you can connect it to your Wifi without any server connection
airgradient.com/onboarding/connect-without-qr/?type=indoor

But you won’t have the calibrations applied by default. If you want to enable those you can do so with a local API call
https://github.com/airgradienthq/arduino/blob/master/docs/local-server.md#pm-25

#3

I apologize if my statements were too dogmatic - I understand that there may be many ways to accomplish an objective with these networked devices. I don’t have such expertise or experience, just a new owner. From my perspective, I was required to connect with AirGradient to start the AirGradient One and I was required to setup an AirGradient account to calibrate the PM2.5 sensor. As I mentioned, the instructions provided by AirGradient on their website were confusing to me. I did not find a simple “Local Setup” page and I did not use the QR code to setup the monitor, but even so the monitor connected directly with AirGradient. I am not against connecting with AirGradient or setting up an account, I was merely reporting one way of getting the monitor working so that others would be able to get their monitors up and running.

As an aside, it seems like the AirGradient instructions are written by employees who have “too much” knowledge of the product - they could use some input from new users. Also, it would be nice to get rid of the in-page buttons and QR codes that do “who-knows-what” to your computer. We have all been trained not to click on in-page buttons for fear of malware.

Bottom line is that AirGradient appears to have a GREAT product which I would highly recommend even if the initial setup can be annoying.

#4

Hi @Buzzer,

Thank you for sharing your feedback and these are very valid points. Much of the setup documentation is still lacking or too ‘techy’ at the moment. Please know that this is something we are currently in the process of improving at the moment.

Your point regarding local setup documentation is also very good and I will bring this up with our team.

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