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

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

#141

Post by rootusrootus »

MaxikCZ wrote: post #45
ignite wrote: post #22

Earlier quoted context omitted.

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.

Thats like having a car that always drives me somewhere I don't want before it drives me where I want. What the actual f*ck. How are people okay with having such garbage in their homes. Why not just buy an analog spring scale...

> Why not just buy an analog spring scale...

Because digital scales have features that analog ones do not. And contrary to an earlier assertion that 'almost all' scales lie to get consistent results, this is very much not true. There are reputable digital scales that do not behave that way.

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

#142

Post by jjoonathan »

aulin wrote: post #36
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

I wouldn't say it's the same. Low cost air quality measurement is difficult. PM is tricky but almost manageable with laser scattering, toxic gases at typical inquinant concentrations are almost impossible to get right with electrochemical sensors, no matter how much money you throw at them. Weight measurement is easy, they could give you precise and accurate results but most customer base doesn't understand anything…

No, they lie to cover up the cheapness and inadequacy of their flextures. "Users can't handle the truth" is a bullshit excuse and you should be ashamed for making it.

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

#143

Post by ilyt »

neogodless wrote: post #112
ilyt wrote: post #104

Earlier quoted context omitted.

Source on that ? Never saw that and just checked my cheapo, it doesn't do it

My Bowflex scale does this. I tend to switch modes / user profiles if I care about accuracy.

See mine is too cheap to have any logic or memory in it

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

#144

Post by rootusrootus »

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"

The Withings scales definitely do not.

Personally, I've only ever had one scale in my life that I thought might be using memory to give false consistency. But even then, it was short-term, not long term. I.e. if you stepped off and back on, it might bias towards giving you the same weight. If you walked away for a bit, then came back with a small extra weight in your hand, it was accurate.

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

#145

Post by rootusrootus »

aSockPuppeteer wrote: post #44
sidmitra wrote: post #19

Earlier quoted context omitted.

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"

Eufy smart scale P2 Pro. $79.99 It has wifi and bluetooth, so it always syncs up with your phone and can track multiple people. I don't really trust the body measurement stuff but use it for measurement per measurement information. The heart rate is kind of nice to track too.

Even cheaper, and IMO slightly more reputable, the $50 withings scale is pretty great, and it's half the price of the version with useless body composition measurements.

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

#146

Post by Cthulhu_ »

whamlastxmas wrote: post #139
stonemetal12 wrote: post #136

Earlier quoted context omitted.

At night you still sweat and breathe. In fact weight loss in general occurs by breathing. Your body gets energy by breaking carbon bonds, then disposes of the carbon via breathing out CO2.

There is zero way your body is losing a quarter pound at night through either process in a room at 70 degrees

A quarter pound is only just over 100 grams, or about two shot glasses; you'll just breathe that out as water vapor, and then some. Plus sweating happens even when you're not feeling moist.

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

#147

Post by Cthulhu_ »

Al-Khwarizmi wrote: post #56
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

That should be outright illegal... Why do they allow equipment that deliberately lies to the user?

I'm not actually sure now you mention it; it used to be a serious crime to mess with weights and scales, when they were used for weighing coins. Probably still is.

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

#148

Post by whamlastxmas »

mnw21cam wrote: post #117
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…

Please could you consider changing the CSS on the article. At the moment, the web page has "display: block" on almost everything, which does exactly what it says on the tin and produces a blank white page, which does make it a little difficult to read the content.

Browser reading mode is good for fixing this

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

#149

Post by DHPersonal »

mnw21cam wrote: post #117
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…

Please could you consider changing the CSS on the article. At the moment, the web page has "display: block" on almost everything, which does exactly what it says on the tin and produces a blank white page, which does make it a little difficult to read the content.

`Display: block` doesn't hide content; that's what `display: none` does.

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

#150

Post by whamlastxmas »

ioulian wrote: post #61

For people who use Home Assistant, I've gone with DIY route with ESPHome [1] and senseair CO2 sensor. You can buy those sensors for +- 26 USD on AliExpress. Together with 5 USD, ESP32 devkit, it's mostly "solder"-n-play. Of course, I only have one of them, so I can't say if they are accurate, but I just need to know if the CO2 levels are normal (+- 400ppm) or high (+1000ppm), to open a window. I have tested it with j…

Can’t wait for the Thread ESP32 units to be better developed
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