Thanks John, I am still wrapping my head around this AQI calculation, and will check it as you describe. For the moment, I am satisfied to know that Whew-Purple is likely to be accurate.
> On 11 Jan, 2025, at 17:33, 'John Kline' via weewx-user > <weewx-user@googlegroups.com <mailto:weewx-user@googlegroups.com>> wrote: > > Hi Dan, > > Please explain how weewx.conf entries could fix the AQI displayed on the > PurpleAir website? > > The AQI you are seeing from my purple extension has the correct pm2_5_cf_1 > EPA correction (computed from the average of the two pm2_5_cf_1 readings of > the two sensors as well as the current_humidity returned in the purple air > reading). The AQI is calculated using the new EPA AQI formula. There is > nothing more you to do with this number. > > I was telling you to look at the documents so that you can manually verify > the AQI the Purple extension is showing. I did this because you are > questioning if it is correct. I don’t know any other way for you to know for > sure without you going through the steps yourself. > > If you satisfy yourself that the Purple extension AQI is correct, then you > can take this up with PurpleAir as to why it is incorrect on their map. When > I last looked at this, PurpleAir was not giving a date for using the new AQI > index. > > John > >> On Jan 11, 2025, at 8:21 AM, Dan Hinckley <d...@suiattle.org >> <mailto:d...@suiattle.org>> wrote: >> >> Thanks John, did the map settings, and will experiment with your links. I >> guess there isn't a way to do that correction in the weewx.conf file then? >> >>> On 10 Jan, 2025, at 13:02, 'John Kline' via weewx-user >>> <weewx-user@googlegroups.com <mailto:weewx-user@googlegroups.com>> wrote: >>> >>> The following settings in the purpleair web app will help you, but you >>> can’t get the correct AQI because PurpleAir hasn’t implemented it. >>> >>> If you want to be sure weewx-purple is showing you a correct AQI, you need >>> to take a current reading from the sensor, apply the pm2_5 correction (one >>> of the two links I previously sent) and then use the other link to compute >>> the AQI. That is what should agree with weewx-purple’s AQI. AQI will show >>> higher in the green range in weewx-purple since the EPA made that range >>> more stringent in the new calculation (among other changes). >>> >>> <image0.png> >>> >>>> On Jan 10, 2025, at 9:24 AM, Dan Hinckley <d...@suiattle.org >>>> <mailto:d...@suiattle.org>> wrote: >>>> >>>> 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 >>>>> <weewx-user@googlegroups.com <mailto:weewx-user@googlegroups.com>> 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 <d...@suiattle.org >>>>>> <mailto:d...@suiattle.org>> 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. >>>>>> >>>>>> -- >>>>>> You received this message because you are subscribed to the Google >>>>>> Groups "weewx-user" group. >>>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>>> an email to weewx-user+unsubscr...@googlegroups.com >>>>>> <mailto:weewx-user+unsubscr...@googlegroups.com>. >>>>>> To view this discussion visit >>>>>> https://groups.google.com/d/msgid/weewx-user/C40F997E-F8DC-452D-9D30-3C8307C08AB1%40suiattle.org >>>>>> >>>>>> <https://groups.google.com/d/msgid/weewx-user/C40F997E-F8DC-452D-9D30-3C8307C08AB1%40suiattle.org?utm_medium=email&utm_source=footer>. >>>>> >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google Groups >>>>> "weewx-user" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send an >>>>> email to weewx-user+unsubscr...@googlegroups.com >>>>> <mailto:weewx-user+unsubscr...@googlegroups.com>. >>>>> To view this discussion visit >>>>> https://groups.google.com/d/msgid/weewx-user/A5AED7CB-4982-4A46-BD84-8A211646C0E5%40johnkline.com >>>>> >>>>> <https://groups.google.com/d/msgid/weewx-user/A5AED7CB-4982-4A46-BD84-8A211646C0E5%40johnkline.com?utm_medium=email&utm_source=footer>. >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google Groups >>>> "weewx-user" group. >>>> To unsubscribe from this group and stop receiving emails from it, send an >>>> email to weewx-user+unsubscr...@googlegroups.com >>>> <mailto:weewx-user+unsubscr...@googlegroups.com>. >>>> To view this discussion visit >>>> https://groups.google.com/d/msgid/weewx-user/2D6FE60B-105B-4524-86BA-F94D046B70F1%40suiattle.org >>>> >>>> <https://groups.google.com/d/msgid/weewx-user/2D6FE60B-105B-4524-86BA-F94D046B70F1%40suiattle.org?utm_medium=email&utm_source=footer>. >>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "weewx-user" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to weewx-user+unsubscr...@googlegroups.com >>> <mailto:weewx-user+unsubscr...@googlegroups.com>. >>> To view this discussion visit >>> https://groups.google.com/d/msgid/weewx-user/A2CF2B8A-E028-48C3-AA6E-2A1357F1F3FB%40johnkline.com >>> >>> <https://groups.google.com/d/msgid/weewx-user/A2CF2B8A-E028-48C3-AA6E-2A1357F1F3FB%40johnkline.com?utm_medium=email&utm_source=footer>. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "weewx-user" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to weewx-user+unsubscr...@googlegroups.com >> <mailto:weewx-user+unsubscr...@googlegroups.com>. >> To view this discussion visit >> https://groups.google.com/d/msgid/weewx-user/C6D4D48D-2209-4E6A-AC38-03E96DA18AB8%40suiattle.org >> >> <https://groups.google.com/d/msgid/weewx-user/C6D4D48D-2209-4E6A-AC38-03E96DA18AB8%40suiattle.org?utm_medium=email&utm_source=footer>. > > > -- > You received this message because you are subscribed to the Google Groups > "weewx-user" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to weewx-user+unsubscr...@googlegroups.com > <mailto:weewx-user+unsubscr...@googlegroups.com>. > To view this discussion visit > https://groups.google.com/d/msgid/weewx-user/EC2EDBD4-6282-4820-8887-8D1921C1F61C%40johnkline.com > > <https://groups.google.com/d/msgid/weewx-user/EC2EDBD4-6282-4820-8887-8D1921C1F61C%40johnkline.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "weewx-user" group. 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