
CO2meter: A Python interface to USB CO2 monitor devices - fanf2
https://github.com/vfilimonov/co2meter
======
joecool1029
This library is for the RAD-0301 meter, marketed as a the co2meter.com mini
CO2 meter. I don't know if it works with any other models but as I have one of
these, I can tell you it works from my linux machines.

You're probably going 'Wow that's expensive for a CO2 meter when I can goto
Aliexpress and get one for $10!' This is actually pretty cheap for a NDIR
sensor which is what one should use for CO2 monitoring. The cheapo $10 sensors
are all VOC sensors that require calibration and can be affected by airborne
pollutants like alcohol.

I believe this is only 100ppm accuracy, the 5-10ppm resolution sensors are
many hundreds of dollars. It's fine enough for casual air quality
measurements.

~~~
Hasz
For $20, you can get the MH Z-19, which is a NDIR type. You can talk to it
over UART, and it comes in a 5000ppm and 2000ppm model IIRC. Decent
documentation, and a good little sensor.

The S8-0053 looks interesting, but I have no experience with it. Also NDIR,
boasts +- 40ppm accuraxy -- the room air might not even be that homogeneous...

The cheap ones are electrochemical, and they're not even that cheap.

[https://sandboxelectronics.com/files/SEN-000007/MG811.pdf](https://sandboxelectronics.com/files/SEN-000007/MG811.pdf)

~~~
polskibus
Problem with it is that it autorecalibrates itself every 24hrs as far as I
remember. It is a problem in room monitoring where you have constant high CO2-
you'd have to take the sensor outside to fix it's reference level.

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lhoff
Iam looking to build my own CO2 Meter for a while know. I even thought about
making a little series as christmas presents. My struggle always was to pick
the right module. Its so hard to pick one and really trust it when you don't
have a reference.

So i thought maybe i give this sensor a shot but i can't find a reputable
source for it. Does someone knows where to buy it or uses another module that
works good?

~~~
411111111111111
i was shopping around last year as well. i finally went with `TFA Dostmann
AirControl Mini CO2 Meter`, you can get the data pretty easily [1] if you
connect it to a raspberry pi (or any linux system, really), so i'm currently
pushing it through MQTT to my HomeAssistant. i was really surprised when i
started monitoring it how closely related my concentration is to the co2 ppa
in my home.

[1]
[https://github.com/maddindeiss/co2-monitor](https://github.com/maddindeiss/co2-monitor)

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Arkanosis
This is a great device. We've never had windows open as much as since we have
it, and believe me, it means a lot of headaches that go away every week
without any coffee or paracetamol.

The next time we move house, proper ventilation is definitely one of the first
things we'll check.

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foobarbecue
Hunh. I've been working with gas monitoring for years (mostly during my
volcanology PhD) and written lots of code to interface with many CO2 sensors,
usually as part of packages that talked to many other sensors. Other than some
weird binary protocols, it was all straightforward, brainless code so I never
thought it needed to be published. LMK if anybody wants a hand with anything
specific.

~~~
bjelkeman-again
What would be a good oxygen air sensor?

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foobarbecue
I've used a few multigas sensors that had O2 when mapping volcanic caves --
Draeger Multiwarn, MultiRAE, National... Safety (?), and CrowCon GasMan. The
CrowCon was my favorite by far. Disclosure: they gave us equipment for free as
sponsorship for our expedition, but it was also honestly just way better than
the Draeger or RAE. Great datalogger built-in with good serial interface,
small, waterproof enough for our uses (the others said IP68 and still died of
water damage). I suspect all CrowCon products are quite good and cheaper than
the competition.

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smcleod
I had a good play with MH-Z19 Co2 sensors and some basic python, here's some
photos (and some old crappy code):
[https://github.com/sammcj/CO2-Logger#photos](https://github.com/sammcj/CO2-Logger#photos)

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platz
I'd be more interested in VOC sensors or PM2.5 sensors.

I feel like PM sensors are easy to understand. I wish i had a better grasp on
VOC/TVOC though.

It's hard to interpret what an elevated VOC from my foobot actually means.

~~~
gh02t
I've used the Plantower PMS7003 sensors for some DIY particulate sensors. I
don't have a lab reference to calibrate against, but they should be pretty
accurate as they are a laser sensor and the readings I got out of them were
very sensible and consistent. Plus they include a tiny fan, which is important
to get good readings. They are easy to use as well, it's just a simple UART
digital interface. I also experimented with the cheaper Sharp IR dust sensors,
but these were much less stable and also require constant calibration; they
were ok for doing simple relative readings but they were clearly very
inaccurate and unstable.

Sensing VOC's accurately is really difficult because most sensors have
radically different (orders of magnitude) sensitivities to multiple compounds
but can't actually distinguish between them. The readings typically get
heavily skewed by the presence of minute amounts of some compound the sensor
is very sensitive to. I tried several sensors and the best I could get out of
them was a relative "good / bad" reading.

~~~
platz
The PMS7003 looks like a great option, thanks!

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gh02t
Interesting, but does anybody know which USB meter is this meant to be used
with? I can't actually find it in any of the docs or links, but maybe I'm
overlooking it.

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warp
This one I think:

[https://www.amazon.com/CO2Meter-RAD-0301-Mini-Monitor-
White/...](https://www.amazon.com/CO2Meter-RAD-0301-Mini-Monitor-
White/dp/B00H7HFINS/)

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xenonite
Great, this works instantly with my recently purchased TFA AirCO2ntrol Mini
[1]. Moderately priced for EUR 65, this gives relatively accurate readings
(the maximum of ±7% or ±100ppm for values <=2000ppm, and ±10% for values
>2000ppm).

[1] [https://www.tfa-dostmann.de/en/produkt/co2-monitor-
airco2ntr...](https://www.tfa-dostmann.de/en/produkt/co2-monitor-airco2ntrol-
mini/)

~~~
xenonite
This device probably is a rebranded RAD-0301 meter.

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toasted_flakes
I have a scd30 from Sensirion, hooked up to a raspberry pi GPIO pins, with a
python script pushing the measurement to InfluxDB and Grafana.

It's super cool how open source projects make it easy to get a great UI,
built-in basic statistics etc, with a few hours of datasheet reading.

Word of warning though: make a proper enclosure for the sensor. Mine is now
perpetually reading 1400 ppm or above after a fairly rough move, even outside
(where it should be about 415 ppm).

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doitLP
Great to see this here. I started monitoring the CO2 levels in my new
apartment after waking up with headaches every night since moving in.

Plugged it in and the alarm started going off immediately at 3000ppm. I use
this package to graph out the readings.

Recently started at a new job and had to educate everyone on the issues with
CO2 build up in meeting rooms. We got each meeting room outfitted with a
sensor and custom monitoring with grafana now.

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awinter-py
cool that it has a timeseries! I'm not familiar with this space but
'timeseries for iot' is a consumer category that I would be a consumer of

(really could be just me though)

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tito
Gut check here, could you share what you want to use a CO2 monitor for?

~~~
losteric
Monitoring CO2 levels? Personally, I want a discrete meter for monitoring
levels in meetings... especially large design/product discussions. I suspect
some of our meeting rooms have poor ventilation and CO2 build up contributes
to increasingly dumb discussions.

~~~
tito
Awesome! That's what I figured but wanted to check. Yes, indoor air in meeting
rooms gets crazy, easily above 1000 ppm.

