You wouldn't just leave some tubes out to monitor air quality because you will only, at best, be able to determine an average. Flying insects will find their way out as the bottom will be brighter than the top and there's a clear flow of air.
>>443210 >The QR codes will be for an internal index, not just for random phones to read.
But all QR codes can be read? Unless OP just means he thought it was broken when he didn't get a URL.
>You wouldn't just leave some tubes out to monitor air quality because you will only, at best, be able to determine an average.
They do exactly this at most airports I have access to, they look exactly the same but are a bit smaller. They are labelled explaining they're monitoring air quality, presumably because people kept reporting them as suspicious. I suppose it makes more sense to want an average air quality on a commercial airfield than a london parkland, though.
The commercial airfield probably has cleaner air than most parks in central London. I'd like to make a more definite statement, but the London Mayor's Office have turned their website black-and-white in tribute to HRH Phil, rendering the official air quality map completely illegible.
They use multiple methods for redundancy and to see different spans of time. That still seems a little wrong to me but I suppose it's easier to stick a test tube somewhere for ad hoc look at how bad traffic pollution is on a given street.
