Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Air quality monitors: paying more does not get you more accuracy

airgradient.com

Post reply on HN
Print view View original

21–30 of 218 posts

Re: Air quality monitors: paying more does not get you more accuracy

#21

Post by kencausey »

sidmitra wrote: post #19
hammock wrote: post #18

Earlier quoted context omitted.

The same is true of digital bathroom scales. In fact almost all consumer grade digital scales have “fake accuracy” built into the firmware that ensures the same exact weight shows up when you step on the scale twice in a row, even if you pick up e.g a quarter-pound weight in your hand the second time

Yes, but do you(or someone else) have a recommendation of which scale does not do this? Something that's not consumer grade, but not "enterprise cost"

There are still inexpensive purely mechanical scales. I wouldn't expect much accuracy from a spring-based scale, but it should be consistent barring significant temperature variation.

Re: Air quality monitors: paying more does not get you more accuracy

#22

Post by ignite »

hammock wrote: post #18
ahaucnx wrote: post #3

Author here. I wrote this article a few weeks ago after discovering that a well known air quality monitor in the market that retails for more than USD 1000 actually uses a PM module that costs less than USD 20. Often people assume that the more expensive, the better but as you can see in the article this is often not the case -especially when it comes to the accuracy of the monitor. If you are looking for an open sou…

The same is true of digital bathroom scales. In fact almost all consumer grade digital scales have “fake accuracy” built into the firmware that ensures the same exact weight shows up when you step on the scale twice in a row, even if you pick up e.g a quarter-pound weight in your hand the second time

I just pick up a five pound weight and step on the scale, then put it down and step off. Step on again, and get he correct weight.

Annoying, but it works.

Re: Air quality monitors: paying more does not get you more accuracy

#23

Post by amatecha »

My three AirGradient DIY units are going strong. They seem very accurate -- strongly correlating with nearby weather stations and online services. Definitely nice to have high-granularity/accuracy details both indoors and outdoors. It's also really interesting to see different "trends" and how different weather conditions correlate with (and/or affect) air quality!

Re: Air quality monitors: paying more does not get you more accuracy

#24

Post by Johnny555 »

I was glad to see that the PurpleAir PA-II sensor (which I have outside and refer to often during wildfire season) has relatively good performance, at least for PM1.0 and PM2.5.

PM1.0 R2 > 0.96, PM2.5 R2 > 0.93

https://www.aqmd.gov/docs/default-source/aq-spec/summary/pur...

Re: Air quality monitors: paying more does not get you more accuracy

#26

Post by ARandomerDude »

sacnoradhq wrote: post #25

PMS9003M is $15 shipped, add another $6 for an Arduino and a display. You can bet the $1000 ones are Better Technology Through Beautiful Marketing and Design(tm). Anyone who pays that deserves to be separated from their money.

> Anyone who pays that deserves to be separated from their money.

This a sad statement and simply untrue. The vast majority of people are in other fields, don’t know anything about hardware, and have never even heard the word “Arduino.”

They don’t deserve to be scammed by con artists using fancy packaging as the hook.

Re: Air quality monitors: paying more does not get you more accuracy

#27

Post by ahaucnx »

smcleod wrote: post #20
ahaucnx wrote: post #3

Author here. I wrote this article a few weeks ago after discovering that a well known air quality monitor in the market that retails for more than USD 1000 actually uses a PM module that costs less than USD 20. Often people assume that the more expensive, the better but as you can see in the article this is often not the case -especially when it comes to the accuracy of the monitor. If you are looking for an open sou…

Out of interest what are your thoughts on the Aranet4? (other than it's quite high price of course).

As far as I know the Aranet uses NDIR CO2 sensor modules from SenseAir. We do use the same brand in our DIY kits and they are very accurate and probably one of the best low-cost CO2 sensors.

Re: Air quality monitors: paying more does not get you more accuracy

#28

Post by AceJohnny2 »

It seems a lot of air quality monitors, such as the PurpleAir PA-II [1] , are just wrapping the Plantower PMS5003 [2], which is a turnkey particle sensor which integrates laser sensors, airflow, and MCU to perform measurements and spit out results on a serial bus.

I'm pretty surprised by the lack of diversity in the "consumer" market.

[1] https://www2.purpleair.com/products/purpleair-pa-ii?variant=...

[2] available e.g. https://www.adafruit.com/product/3686

Re: Air quality monitors: paying more does not get you more accuracy

#29

Post by ruph123 »

I would not recommend the Airgradient diy kit to anyone. Have been using one for a while but the CO2 sensor is really unreliable and often spits out wrong values. VERY OFTEN. Last time this issue was wildly discussed by people using it e.g. in the link below which is using Prometheus but also in the forums of airgradient. All with no solution.

https://github.com/geerlingguy/airgradient-prometheus/issues...

Re: Air quality monitors: paying more does not get you more accuracy

#30

Post by lajupechere »

sidmitra wrote: post #19
hammock wrote: post #18

Earlier quoted context omitted.

The same is true of digital bathroom scales. In fact almost all consumer grade digital scales have “fake accuracy” built into the firmware that ensures the same exact weight shows up when you step on the scale twice in a row, even if you pick up e.g a quarter-pound weight in your hand the second time

Yes, but do you(or someone else) have a recommendation of which scale does not do this? Something that's not consumer grade, but not "enterprise cost"

My withings is constantly .2 fluctuating. If it’s faking that I’m going to chuck it out the window. It’s a very good scale, in aggregate the readings are useful.
Post reply on HN