5 ms·
I remember discussing this a while back on HN, and one issue was that consumer-grade CO2 meters aren't reliably calibated. So just curious for my own designs,
by CoastalCoder 5y ago
I remember discussing this a while back on HN, and one issue was that consumer-grade CO2 meters aren't reliably calibated.
So just curious for my own designs, how certain are you about those ppm numbers you listed?
- OJFord 5y agoNot GP (nor a metrologist) but 50% reduction is surely the important thing anyway, in a home setting, not the absolute figures? I don't think the curve could be much off, since they work by counting particles, so if it's reading high at 800ppm then it should be reading just as high at 500ppm right?
- CoastalCoder 5y agoI agree that presumably less CO2 is better than more. I'm thinking that the specific CO2 concentrations matter if one wants to relate the readings to various research on human mental performance.
- eightysixfour 5y agoI have tested quite a few against calibrated commercial hardware at this point and they’re not as poorly calibrated for CO2 as you would think. The particulate counts and VOCs are usually only good for comparative measurements from the same device in my experience, and even then the drift is quite large.
- JohnJamesRambo 5y agoAll my CO2 meters read about the same as the one in my grow room that controls the CO2. I don’t think that is a big problem.
- mdp2021 5y agoI am desperately looking for one for the car, do you have anything to suggest? Also, I am finding products that seem to require an Android or iOS device to work: no. They must be independent. If they had a webserver, nice idea, but all connections should be unrequired and switchable to off.
- CoastalCoder 5y agoYou might need to specify which kinds of gasses or particles you need to measure. I would have assumed CO2 from the context, but since you mentioned cars I'm wondering if you mean CO, VOCs, and/or PM32.
- mdp2021 5y agoCorrectly guessed, mainly CO2 (breathing). I did not know that CO can be relevant in the car. But of course, the more is evalued, the better. In fact, for example, I had similar concerns for CO for the house (free flames).
- CoastalCoder 5y agoMy understanding is that in a car, CO is normally a concern only if exhaust gas is somehow leaking into the passenger compartment. Unless your car has the fans off and the windows rolled up for a really long time, I'd be surprised if CO2 was something you need to worry about. Maybe if you're sleeping in it with the windows rolled up? CO in the house is definitely a concern. If you have a fireplace, woodstove, or furnace with a properly functioning chimney, you're unlikely to run into problems AFAIK. But people die every winter because they used a propane grill, or kerosene heater, or gas stove/oven in their house without proper ventilation. Or used a wood stove with ineffective / blocked chimney. So in colder climates having a functioning CO meter seems like a no-brainer.
- mdp2021 5y agoExactly. In the car, it may happen in winter that you could be working for some time with little ventilation. You may at some point feel dizzy, and realize you would like a meter to get the feedback that can teach you be more aware of the air quality, to regulate the balance between letting the hot air inside escape and letting the fresh air (both senses) in. In the house, similar awareness could be beneficial. But I have not yet found a decent product. It is unacceptable that one is supposed to have a Google account or similar in order to read a ruler or configure a blender.
- CoastalCoder 5y agoAny chance you could share some of your findings? They'd be super helpful to some of us.