I bought a PurpleAir sensor model PA-II in March, 2017 - the price was somewhat lower then.
Other than for a period of about a month, the sensor has been continuously uploading its data to Thingspeak cloud storage - the sensor was taken offline for about one month as I was having some ‘communication’ problems with the sensor designer/reseller and refused to supply my data without being able to access my data back.
I have been able to download the data in the JSON format from the Thingspeak cloud storage, but that data is limited to particulate matter 2.5 - I have been trying to get clear and concise instructions (from the designer/reseller) on how to download additional information from the Thingspeak cloud storage (I have sent 5 messages over the past days with useless replies).
For the past 2-3 weeks, as British Columbia, Canada was doing through an unusually large number of forest fires, I was able to provide (calculate/produce) continuous air quality indexes for my immediate area and post those results on my weather pages - got a few messages of appreciation from my neighbours as AQI reached levels of 150+.
My PurpleAir sensor has been reliable. It has two sensors built in providing slightly different PM2.5 values - still nice to have the two sensors as one of my sensor gave unrealistic readings until I power it off, cleaned out a small invader and power it back on.
The PurpleAir sensor has also three completely useless sensors (temperature, humidity and pressure) - because of the heat produce by some of the components (chips) inside the unit, (currently) the temperature is off by 8 degrees C, the humidity is off by 29% and the pressure is off by 43.32 hPa. I have been asking the designer/reseller to remove those values from the information screen displayed when a location on the Google map is clicked, but, so far, the reply has been ‘I will consider it’!
I am not writing that the PurpleAir is a bad unit - I have really enjoyed to have some constant reading of the AQI over the past weeks.
But, because of the poor and incomplete technical support (in my view), I cannot recommend the purchase of the PurpleAir sensor - maybe in a few days (or it could be weeks) when I am able to retrieve most of the data uploaded by my PurpleAir sensor, I might change my recommendation…
Brian, the data from the PurpleAir sensor is continuously uploaded to the Thingspeak cloud storage - that is where Weather Display could be ‘pulled’ in either the JSON of XML format. But, as I wrote above, I have been able to get only a limited quantity of data so far…
Here is the link to my data on the Google map: Tzouhalem/Maple Bay