[HN Gopher] Low-cost open source device can measure air pollutio...
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Low-cost open source device can measure air pollution anywhere
Author : GavCo
Score : 91 points
Date : 2023-03-16 18:44 UTC (4 hours ago)
(HTM) web link (news.mit.edu)
(TXT) w3m dump (news.mit.edu)
| l1am0 wrote:
| This feels like old news. Built such a thing for a german hacker
| initiative like 7years ago. Back then sub 50EUR and still runs.
|
| Data available at luftdaten.info
|
| https://sensor.community/de/sensors/airrohr/
| MandieD wrote:
| We built those and got them running one evening at a Meetup in
| Erlangen - looks like they had to switch to a
| temperature/humidity sensor that requires soldering the pins
| on, because the ones we used back then came ready to plug in,
| not a soldering iron in sight.
| uoaei wrote:
| Official repo:
|
| https://github.com/MIT-Senseable-City-Lab/OSCS
| mistrial9 wrote:
| there is an old man in Berkeley who has made very good money for
| more than thirty years, designing and selling these. No, he does
| not want to "open source" it (I tried).
| grozzle wrote:
| It would be useful if headlines said "~$10", "sub $100", "sub
| $1000" et cetera, instead of vague terms like "low-cost".
| cinntaile wrote:
| According to the linked paper in the article it's <2500usd.
|
| https://doi.org/10.1016/j.atmosenv.2023.119692
| cwkoss wrote:
| I wouldn't call that 'low cost'
| Karawebnetwork wrote:
| Link to project website: https://senseable.mit.edu/flatburn/
|
| Link to assembly guide: https://github.com/MIT-Senseable-City-
| Lab/OSCS/blob/main/Bui...
|
| Link to bill of materials:
| https://docs.google.com/spreadsheets/d/1-fR-0hTxHKbjaRf8DbH6...
|
| Naively searching for every lines of the bill of materials gives
| me around $300, with a handful of items being around $50 and
| everything else under $5. I'm sure a hobbyist could find the
| parts for cheaper, especially things like individuals connectors
| that I found for around $5. I've seen them go as low as $0.25
| when bulk purchased.
|
| Disclaimer: it's possible that some SKUs led me to the wrong
| products. I am not into electronics. I encourage you do to the
| same exercise before drawing conclusions.
| clnq wrote:
| Not to undermine the DIY aspect which could be fun, but it
| looks like you could buy an Atmotube for about half as much (if
| you take the research survey) -- https://ukstore.atmotube.com/.
| Though it doesn't register noise levels.
|
| They can also build you an Atmocube which can measure noise and
| a few other things for $200-$500 based on what I found online.
| theaussiestew wrote:
| Impressive, I've been wanting to build a portable version of this
| for a while now. It would look like a smart band but integrate
| environmental sensors and the users would then be aware of how
| their environment is affecting them. They would also have the
| option of contributing their data to a collective dataset.
| dariosalvi78 wrote:
| I had a similar DIY project, also using some Alphasense sensors,
| + some cheaper metaloxide ones. It was somewhat promising, but it
| needs long-lasting colocation studies and, after I moved to
| Sweden, I lost any support from the local authorities and gave
| up. https://bochovj.wordpress.com/tag/air-quality/
| Rebelgecko wrote:
| How does this compare to something like an Airgradient, which you
| can put together for like $50? More detail about what constitutes
| the PM2.5 or PMn particles you're measuring?
| gnramires wrote:
| Can't find the air quality sensor on their bill of materials
| shrx wrote:
| The Readme file [1] on their GitHub repo contains this bill of
| materials:
| https://docs.google.com/spreadsheets/d/1-fR-0hTxHKbjaRf8DbH6...
|
| This lists a "particle module", a temperature sensor and some
| other seemingly irrelevant sensors (GPS, accelerometer).
|
| [1] https://github.com/MIT-Senseable-City-
| Lab/OSCS/tree/main/Bui...
|
| edit: looks like the "particle module" is just a LTE/BT
| communication module, so really there don't seem to be any
| environmental sensors other than for temperature.
| detaro wrote:
| You are only looking at the list for the main board, the air
| quality sensor carrier is the second sheet of the doc.
| adolph wrote:
| It only includes a particulate matter sensor and "Analogue
| Front End (AFE) Alphasense A4 Air Quality Gas Sensors" but
| not the sensors to use.
| gnramires wrote:
| Thanks!
| ivarvong wrote:
| There's a mention of the SEN5X here: https://github.com/MIT-
| Senseable-City-Lab/OSCS/blob/main/Bui...
| antoniuschan99 wrote:
| I also see an alphasense afe, and bme280
| e44858 wrote:
| The particulate sensor is Sensirion SPS30, mentioned on the AQ
| Ext Board tab in the spreadsheet.
| gniv wrote:
| The key word -- which is missing from the PR title, but is in the
| paper title -- is "calibration". The novelty is there. Apparently
| this is a big problem due to varying humidity levels.
| Havoc wrote:
| Not just humidity - CO2 equivalent sensors are also quite fond
| of drifting
| AceJohnny2 wrote:
| Usual disclaimer that MIT's PR dept is really effective (I've
| stopped paying attention them because of so much hype), and
| there's quite a chasm between a proof of concept and a mass-
| market device.
| alsodumb wrote:
| Yup, they are really good.
|
| The Open Agriculture fraud is a living example:
| https://gizmodo.com/mit-built-a-theranos-for-plants-18379682...
| gumby wrote:
| That one was supercharged by the Media Lab's PR organ. But
| even without that assistance, the regular MIT "news" office
| is head and shoulders above its peers in making the trivial
| appear transformational and the outstanding appear...boring.
|
| My favorite was a publicity piece about a new proof for the
| behavior of higher-order manifolds with some absurd
| justification as to why you should care, something like how
| it would revolutionize battery electrodes or something like
| that.
|
| PS: "living example" was a nice touch.
| alsodumb wrote:
| Hahaha I was worried no one's gonna get my pun.
| jl6 wrote:
| I don't know if this is the device to do it, but the premise is
| solid: create awareness that air pollution is a real thing
| affecting specific areas in which _you_ are breathing right now,
| not just an abstract bad thing that may or may not be happening
| somewhere to someone.
| cactusplant7374 wrote:
| I'm debating buying one for myself so I can judge whether air
| pollution is effecting my asthma. You can find AQI for a lot of
| cities but it appears the calculation often isn't done with
| local devices. Satellite imaging?
| photochemsyn wrote:
| This sounds highly implausible for anything other than very crude
| and not-very-useful measurements. Quantifying air pollution is a
| fairly hard problem, chemically speaking. The composition of
| particulate matter is highly diverse as it may arise from a wide
| variety of sources, i.e. agricultural, industrial, wildfires,
| diesel engines, etc. Just looking at the particulate PM2.5/PM10,
| broadly speaking there's the organic carbon fraction and the
| inorganic metal fraction. The former is highly complex, e.g.:
|
| > "The considerably increased chromatographic resolution in GCxGC
| [gas chromatography] allows separation of many UCM [organic
| carbon] compounds while the TOFMS [mass spectrometer] supplies
| mass spectral data of all separated compounds. However, the data
| sets are getting enormously complex. In a typical PM2.5 sample
| from Augsburg _more than 15,000 peaks can be detected_... "
|
| https://www.sciencedirect.com/science/article/abs/pii/S00219...
|
| Some particulate matter may have a heavy metal fraction, some may
| not and that's also not easy to determine (but was a major factor
| in leaded gasoline pollution). Here's a sample of the kind of
| work that has to be done to get reliable measurements:
|
| > "...using quadrupole inductively coupled plasma - mass
| spectrometry (q-ICP-MS). We report improved measurements of key
| aerosol elements including Al, V, Cr, Fe, Ni, Cu, and Zn in
| airborne coarse particulate matter (PM10)... This technique was
| used to determine the elemental composition of over 150 PM10
| samples collected from an industrialized region in Houston, TX."
|
| https://www.sciencedirect.com/science/article/abs/pii/S00032...
|
| On top of that there's nitrogen oxides and PAN, ozone, etc. The
| only relatively inexpensive recent innovations seem to be the use
| of drones to collect samples for lab analysis (would have been
| useful in East Palestine).
|
| Getting accurate measurements of all the species involved in air
| pollution requires a modern analytical lab packed with equipment
| that costs hundreds of thousands of dollars and highly trained
| technicians to operate. The press release and snippets from the
| paper don't address such important details at all.
| Severian wrote:
| Not only that, but they are deployed on top of automobiles,
| where the air quality in the surrounding air is going to be
| worse to begin with. I understand the benefits of using GPS,
| but I don't see where they mention this being an issue.
| ddulaney wrote:
| Most definitely it's hard to dig into the actual composition of
| air pollution. But "how much PM2.5 is in the air", while
| definitely crude, is still extremely useful. That said, decent
| sensors for PM concentration are already pretty cheap (<$100
| for a module; ~$100 for a full package), so unless the price is
| going way down it's unclear how useful this particular
| innovation is.
| ckocagil wrote:
| A lot of these cheap, portable sensors "cheat" in one way or
| another. E.g CO2 sensors that assume they'll be subject to open
| air once every few days, using that minimal CO2 value as a
| baseline. So while they give numbers which can be useful if the
| user is aware of its limitations, they're far from being
| analytical tools.
|
| In contrast PM is pretty easy to get right. Shine laser, count
| particles.
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