I thought it might be something along those lines. How would I tell is the PA 
unit is using the new correction?

My unit appears here 
<https://map.purpleair.com/air-quality-standards-us-epa-aqi?opt=/1/lp/a10/p604800/cC0&select=196617#11/43.7324/-69.8443>
 on the PA map, and the page displaying your extension output is here 
<https://suiattle.net/CapeSmallHarborWeather/sp/bt/purple/index.html>.

> On 10 Jan, 2025, at 11:51, 'John Kline' via weewx-user 
> <[email protected] <mailto:[email protected]>> wrote:
> 
> There are two reasons these can differ.  One, the PurpleAir map you are 
> showing is a 2m average while the weewx-purple loop packets are the most 
> recent reading.  Also, the EPA has updated the AQI calculation (see: 
> https://www.epa.gov/system/files/documents/2024-02/pm-naaqs-air-quality-index-fact-sheet.pdf
>  
> <https://www.epa.gov/system/files/documents/2024-02/pm-naaqs-air-quality-index-fact-sheet.pdf>
>  ).  Weewx-purple has been updated with the new AQI calculation while the 
> PurpleAir map has not been.
> 
> A third reason could be if the PurpleAir map is not using the EPA correction 
> (which corrects pm2_5)—see 
> https://www.epa.gov/sites/default/files/2021-05/documents/toolsresourceswebinar_purpleairsmoke_210519b.pdf
>  
> <https://www.epa.gov/sites/default/files/2021-05/documents/toolsresourceswebinar_purpleairsmoke_210519b.pdf>
>  .  I cannot tell if this is so from your screenshot.
> 
>> On Jan 10, 2025, at 6:40 AM, Dan Hinckley <[email protected] 
>> <mailto:[email protected]>> wrote:
>> 
>> When I access my PA unit directly, the readings I see are different from 
>> the one generated by the John Kline extension 
>> <https://github.com/chaunceygardiner/weewx-purple>.
>> 
>> When I check right after WeeWx has generated new files on each loop, direct 
>> access to the PA shows this:
>> 
>> <Screen Shot 2025-01-10 at 09.37.37.png>
>> 
>> And the WeeWx-Purple displays this:
>> 
>> <Screen Shot 2025-01-10 at 09.37.56.png>
>> 
>> I don't know enough about how the AQI is calculated to know if this 
>> discrepancy is normal or is something else.
>> 
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