Hey @warren that is cool. Always wondered about that monitor. So, right now in Philly today we have Plume app reading 57 AQI with a PM2.5 reading of 32. Are you near a port area with lots of trucks?

Providence is a port, but @jiteovien said there are a number of PM sources locally apart from the port, i think!

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Hey @warren that is cool. Always wondered about that monitor. So, right now in Philly today we have Plume app reading 57 AQI with a PM2.5 reading of 32. Are you near a port area with lots of trucks?

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@zengirl2 Yeah, the area the office is is actually near the part of Providence (the port) with the most industrial polluters. See the map below of EPA-regulated industrial polluters in Providence.

However, the PurpleAir is known to read higher values then actual. The Rhode Island Dept of Environmental Management forecasters are saying it is currently AQI 65 but that there was a high today of 115 in Providence.

@jiteovien Ah, this is helpful--what a great testing zone. Interesting to hear how Purple is a bit high on readings too. Did the sensor need to be acclimated in any way?

@zengirl2 The PurpleAir folks say that the sensor come "factory calibrated." I am certainly skeptical of that because its been shown that humidity can affect readings. The device does include a humidity sensor but it is unclear if they are using that data to post-calibrate the readings or not.

But another thing to consider when comparing the "official" numbers to the PurpleAir, at least in RI, there are only 2 federal monitors measuring PM in the city. It is very likely, in my opinion, that there could be an area that there network is not adequately capturing with their forecasts.

@jiteovien I find that there are not many official monitors in Philly either. So, I'm very interested in air monitoring just to see how the numbers look with a DIY unit. I haven't tried yet. BTW, have you gotten hold of a Plume system yet to test?

@zengirl2 Nope, I haven't tried a Plume

Just a note that at 12:42 today (friday) two people with leaf blowers went by clearing the sidewalk and there was visible dust kicked up. Curious to see if it shows up in the data!

Oh wow, I literally saw the dot change from yellow to orange as I watched the map! You can see the spike too:

OK interesting and now it's green again, and i guess because of averaging, the spike doesn't appear as high anymore?

@jeffalk does this seem right about the averaging?

@zengirl2 I agree, the ambient network can be a little scarce in Philly, we have six PM 2.5 monitors measuring at different intervals. Here's some more information about the ambient air monitoring network plan, and here's the link to real-time values collected at each station by AMS (the local regulatory agency). When you click a station on the map it should give you a real-time value for each pollutant measured there.

I'm heading up some of Clean Air Council's air monitoring work in Philly, so we have some open PurpleAirs already deployed here. We're focusing on community monitoring in the Kensington (19134) area targeting local sources like scrapyards and construction. We've also given one to AMS to collocate with one of their regulatory sensors (this one is set to private currently). I'll see if I can draw up a more in-depth research note at some point about what we're doing in the area.