Hi & query about potential other sensor types

Hello!
First post…
A couple of months ago I built two airrohr units and they’ve been tootling along fine here in Bristol since (one at home, one at my workshop).
What I’m curious about is whether there are other types of sensor possibilities - in particular other air quality factors such as NOx. I’ve probably got plenty of further reading up to do + am interested to see there’s the Noise monitor one too which might be useful for my street where we’re trying to investigate noise & air pollution from local idling trains.
Any ideas or pointers gratefully received!
By way of introduction, I work in analogue audio electronics - haven’t really done anything micro based (at least not programming from scratch) for 15-20 yrs (already!).
Cheers, Tom

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Hi,
Thanks for your message.
Concerning the other types of sensors, we have still not found for ex. some gaz sensors which could be used efficiently according to their datasheets (T° of use, spread of the values…etc.). We had a one shot project for NO2 with diffusion tubes: http://no2.maps.sensor.community/. To be continued…
The noise sensor works perfectly even if it is a bit more complicated and expensive to build. Their is also a parallel project for radiation: https://multigeiger.citysensor.de/
If you want to participate in our weekly call (Wednesday 20:00 CET)…
Regards

Cool - thanks for your reply.
Yes, it seems that NOx is slightly hard for various reasons - I’ve seen a few so far, but haven’t yet got my head around what parameters are important. That is fantastic that your community have focused on a few cities to get decent spread around them - I’d love to get Bristol involved if the project continues.
I came across the interesting Airly project, though it isn’t DIY or particularly cheap (maybe viable for community). Clearly something quite pro like this is antithesis of your open community approach, though the calibrated/processed nature of the data certainly would have advantages.
I saw a few sensors like the Ampenol MICS ones, like MICS-6814, for which there are project boards made. Something for me to dig into more… but maybe people have already examined and discarded it?
I would hope to join discussions/weekly-call sometime – time/parenting allowing :wink:

As Polish citizen I would say that Airly (from Kraków, Poland) made a huge impact on air pollution awareness in Poland. However their decision to not share the data with most popular Polish air quality app - Kanarek App was very controversial. From my point of view theirs number 1 priority is money and worldwide expansion for more money. Airly recently got a huuuuuuuuuuge funding. So they will be everywhere soon.

Airly business models is way different that Sensor.Community approach. Sensors cost about 1600 PLN (≈350€). They comes with monthly fee. Sensors itself use Plantower PMS5003 with AM2302 (DHT22). They have a cleaver machine learning algorithms for weather forecasting in given location where sensor is deployed.

Don’t get me wrong. I have love~hate relationship with Airly. They do a great job, but they could really share a bit more data with community - especially when their funding comes strait from public institutions. I pay in my taxes for Airly sensors. And yet the data is available only via theirs website.

Thanks for that response - as someone newly learning in these areas, that is interesting & understandably conflicting.

Interestingly they say they heat the air entering the PM sensor.
Is this necessary to get accurate results?

There is an interesting thread on this topic: click

They don’t use heater in their most popular design.

So heater not needed?

Is the Plantower PMS5003 a better device than the Nova SDS011?

Do you get many issues with bugs and spiders?

Hi, this is very interesting. I would like to add a radiation sensor to my airrohr. Where can I find further information on this topic?
Many thanks in advance,
Ralph

The map: https://multigeiger.citysensor.de/
The data is sent to the DB of Sensor.Community but there is currently no visualization for radioactivity on the main map.

To build:

Hi, is there more information about this project? What are those diffusion tubes? How to build them? What happened with them after the project ended? Were you satisfied with the results? Why it was stopped?

From the NO2 page:

The #NO2Tubes-Campaign is a (for now) one shot project of the global open environmental data platform Sensor.Community.

Between the 1st of October and the 31st of October 2020 local teams placed in the displayed 9 cities in Europe >250 NO2 diffusion tubes in order to measure the average daily concentration of this gas in the air.

The blue dots display the locations of official measurement stations.

The other dots display the NO2 diffusion tubes measurement locations and the color is in relation to the measured value.

You can check the current official measurement for NO2 on this map of the EEA. Change the pollutant for NO2 to have this being displayed.

Under Directive 2008/50/EU, the standards for NO2 are:

  • 200 µg/m³ for an averaging period of 1 hour
  • 40 µg/m³ for an averaging period of 1 year

For a better lisibility of the data, we used the scale of the Air quality in Europe — 2020 report of the EEA (page 72).

Contact us if you have feedback or want to get in touch with us:campaign02@Sensor.Communit


The diffusion tube are passive system which react with the air for a 1 month time span. They can’t be build, you have to buy them and them send them back for analyze at the provider’s.


We were satisfied but we would have wanted to do some further measuring. A map with a lot of analysis collected at some institution is currently developed.

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Ahh, ok, so you need to replace them each month to keep it going, and you get only a single number per month - seems not a very convenient solution.

Maybe someone knows what NO2 sensors are used by Airly?

I know that the PM sensor is a PMS5003 but I can’t find any information about the NO2 sensor.

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