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Comment by jcrben | Hacker News Reader

A warning: the cheap air monitors don't monitor particle count, just CO2. If you're allergic to pollen you expose yourself to it by opening windows. I've had to help a couple friends who used this and ended up sneezing and sniffling like crazy.

I have the Dylos monitor which does monitor particle count so you can see it drop when your air filter is working https://www.amazon.com/dp/B08F2YM8SM/ref=cm_sw_r_apan_glt_i_...

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You really don't need a 270 usd device for particle count.

A PM2.5 particle count sensor is like 25 bucks and temp/humidity/pressure another 10, so you can DIY this quite cheaply with a raspberry if so inclined.

https://www.amazon.com/WINGONEER%C2%AE-Precision-Quality-Det...

https://www.amazon.com/bobotron-Compatible-Temperature-Atmos...

Good point. I think you can get them embedded in consumer devices for pretty cheap lately; I bought the Dylos about a decade ago.

I have both the Dylos and other sensors. The Dylos is a very sensitive instrument that reports raw counts every second. There is no smoothing, no translation to PM2.5 scale. For the paranoid type it works REALLY WELL for providing direct feedback on the impact of an air filter- or on the impact even of minor contractor work. PM 2.5 sensors- quality ones- have their place. But the difference is kind of like the difference between reading labels and following FDA guidelines on nutrient intake vs getting a blood screen. Sometimes you want the blood screen. Dylos is a good device for that.

I'd imagine the Dylos will have better components and better calibration, so should provide superior accuracy.

Not convinced they're all that different though - both laser based particle counters, and results correlate pretty well in studies [0].

Certainly wouldn't trust a cheap SDS011 sensor for anything that really matters, but wouldn't characterize it as nutritional label vs blood screen either.

[0] https://www.researchgate.net/publication/337399372_Dynamical...

> raw counts every second. There is no smoothing, no translation to PM2.5 scale.

Slightly confused as to what you mean by this. Particle measurements via laser are by necessity over time and thus smoothed. I guess you could look at raw counts in a given time, but people use per millions because its more meaningful...else you'd need to consider fan speed to make it comparable and manually adjust air pressure/temp yourself.

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