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Open Source Outdoor Air Quality Monitor

airgradient.com

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Re: Open Source Outdoor Air Quality Monitor

#31

Post by zerof1l »

I don't see any benefit in this product having two identical sensors side by side. Based on the datasheet, the reading between sensors is quite consistent, meaning that there's no improvement in accuracy. What would be better is to have two different sensors, one of which actually counts PM 10.0.

A little-known fact about these air quality sensors is that they don't actually measure three different particle sizes, they typically measure the smallest one and then return some statistically determined value for the larger ones.

[1] https://www.digikey.jp/htmldatasheets/production/2903006/0/0...

Re: Open Source Outdoor Air Quality Monitor

#32

Post by philshem »

traceroute66 wrote: post #5

Time for the usual reminder that there is a search function on the bottom of every single YC page. Air gradient has been extensively discussed here multiple times already.

> …there is a search function on the bottom of every single YC page

Weird, in all seriousness, I never noticed.

Re: Open Source Outdoor Air Quality Monitor

#33

Post by ahaucnx »

zerof1l wrote: post #31

I don't see any benefit in this product having two identical sensors side by side. Based on the datasheet, the reading between sensors is quite consistent, meaning that there's no improvement in accuracy. What would be better is to have two different sensors, one of which actually counts PM 10.0. A little-known fact about these air quality sensors is that they don't actually measure three different particle sizes, th…

There are two main advantages of having two sensors:

a) Data quality: You can detect if one sensor fails as the two readings will start to deviate and then replace the faulty one

b) Extend the life of the monitor: The PM sensors with the laser and optics have a limited life. By having two inside, you can alternate the measurement and put them in sleep mode inbetween. Thus extending the life of the monitor.

Re: Open Source Outdoor Air Quality Monitor

#35

Post by cyberax »

stevep001 wrote: post #7

I'd be a buyer if you had an indoor unit with a radon sensor.

Why would you want a radon sensor in a product that does constant monitoring?

Radon concentration is not a transient state, and you need to measure it for a fairly long time to get a good idea of the true concentration.

Re: Open Source Outdoor Air Quality Monitor

#36

Post by cyberax »

ahaucnx wrote: post #2

I'm the founder of AirGradient and last year we have decided to focus our company on open hardware air quality monitors that we produce professionally. Our outdoor monitor Open Air has been designed from the start as an open hardware project with a beautiful plastic injected enclosure to demonstrate that open source hardware can look and perform on the same level like traditional products. We do also work intensively…

How good is the calibration for your temperature and humidity sensors?

I'm absolutely miffed by the poor-quality sensors that are off by 10% humidity and 2-3C of temperature. I bought several sensors to try and find the best ones, and now like a man with two watches I'm never sure what the actual time is.

Re: Open Source Outdoor Air Quality Monitor

#37

Post by cyberax »

ahaucnx wrote: post #33
zerof1l wrote: post #31

I don't see any benefit in this product having two identical sensors side by side. Based on the datasheet, the reading between sensors is quite consistent, meaning that there's no improvement in accuracy. What would be better is to have two different sensors, one of which actually counts PM 10.0. A little-known fact about these air quality sensors is that they don't actually measure three different particle sizes, th…

There are two main advantages of having two sensors: a) Data quality: You can detect if one sensor fails as the two readings will start to deviate and then replace the faulty one b) Extend the life of the monitor: The PM sensors with the laser and optics have a limited life. By having two inside, you can alternate the measurement and put them in sleep mode inbetween. Thus extending the life of the monitor.

Just a note: can you stagger the sensor time a bit unevenly?

Instead of 50%/50% time split, can you do something like 40%/60%? This reduces the risk of both sensors failing at once because they have approximately the same duty time.

Re: Open Source Outdoor Air Quality Monitor

#38

Post by traceroute66 »

triyambakam wrote: post #14
traceroute66 wrote: post #5

Time for the usual reminder that there is a search function on the bottom of every single YC page. Air gradient has been extensively discussed here multiple times already.

I appreciate when things come up again. Obviously enough people either haven't heard of it or want to talk about it again for it to be upgoated to the front page.

> I appreciate when things come up again

My own position on this is that there is difference.

If, like today's post, we're talking about what in forum-slang would be a "bump" post, then as far as I'm concerned it has near-zero value. Its basically just attention seeking if we're being honest.

Meanwhile if it's re-posting a link but in the context of a significant change, for example a new version with major new features, then obviously it's a different kettle of fish altogether. That's obviously perfectly fine.

Re: Open Source Outdoor Air Quality Monitor

#39

Post by cvwright »

ahaucnx wrote: post #2

I'm the founder of AirGradient and last year we have decided to focus our company on open hardware air quality monitors that we produce professionally. Our outdoor monitor Open Air has been designed from the start as an open hardware project with a beautiful plastic injected enclosure to demonstrate that open source hardware can look and perform on the same level like traditional products. We do also work intensively…

This is random but I’d love to hear more about what’s involved in designing an enclosure and getting it manufactured at scale.

Re: Open Source Outdoor Air Quality Monitor

#40

Post by ahaucnx »

traceroute66 wrote: post #38
triyambakam wrote: post #14

Earlier quoted context omitted.

I appreciate when things come up again. Obviously enough people either haven't heard of it or want to talk about it again for it to be upgoated to the front page.

> I appreciate when things come up again My own position on this is that there is difference. If, like today's post, we're talking about what in forum-slang would be a "bump" post, then as far as I'm concerned it has near-zero value. Its basically just attention seeking if we're being honest. Meanwhile if it's re-posting a link but in the context of a significant change, for example a new version with major new featu…

This page about the monitor is brand new and contains quite a lot of information that has never been published/posted before, e.g. the exact specs of the monitor and explanations about the enclosure design.
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