Earlier quoted context omitted.
Because the user otherwise will spot the discrepancy and pronounce "these scales are rubbish" (which in a way they are).
So why not fix the scale so it isn't rubbish?
That costs more, and the consumer wouldn’t buy it.
Air quality monitors: paying more does not get you more accuracy
131–140 of 218 posts
Re: Air quality monitors: paying more does not get you more accuracy
#132Re: Air quality monitors: paying more does not get you more accuracy
#133Earlier quoted context omitted.
Because the user otherwise will spot the discrepancy and pronounce "these scales are rubbish" (which in a way they are).
So why not fix the scale so it isn't rubbish?
Cost.
They system has found an equilibrium: customers are willing to pay ~$X for a scale. For $X you can afford Y accuracy.
If you increase the accuracy, great, but now your scale costs more then $x.
Re: Air quality monitors: paying more does not get you more accuracy
#134Earlier 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"
The Nintendo Wii balance board is the only good scale you can get and it isn't expensive. A balance board, Wii, and small TV is probably around $500.
You don't even need the Wii itself! You can connect to the balance board via Bluetooth, and there are several libraries out there that can read out its data (and that of the Wiimotes as well).
Re: Air quality monitors: paying more does not get you more accuracy
#135Author 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…
> 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.
This may be true for off the shelf air sensors, but in general the base cost of the sensor is not necessarily correlated with achievable accuracy. There are even manufacturers like Maxim who will sell you sensors for cheap, but you pay a lot to license firmware to get the best performance (and in this case actually a smoke/particle detector if I remember right - the MAX30105).
You might pay thousands for a third party calibration on top of the OEM device. For example an infrared calibration target is a puck of coarsely machined metal, a heater cartridge and some black paint, but you're paying $$$ for NIST traceability, guaranteed measurements of the emissivity, etc.
https://hackaday.com/2017/04/11/ask-hackaday-how-does-this-a...
https://www.sciencedirect.com/science/article/pii/S002185022...
Re: Air quality monitors: paying more does not get you more accuracy
#136Earlier 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 can recommend Xiaomi Smart Scale 2 ( not the body composition one, it's nonsense). It is very accurate and repeatable. So much so, that you can see your weight drop after you go to the toilet. It is fascinating how much one's weight fluctuates during the day (or night which is even weirder if you don't eat/drink anything!)
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.
Re: Air quality monitors: paying more does not get you more accuracy
#137Author 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…
I am actually not surprised as ai noticed similiar non-correlation of price and quality with different products.
For headphones someone made a small analysis regarding at leat frequency response and price: https://pubs.aip.org/asa/jasa/article/141/6/EL526/917945/No-...
Re: Air quality monitors: paying more does not get you more accuracy
#138Earlier quoted context omitted.
Wouldn't just correction factor be enough ? If device takes constant power it should also heat the sensor by constant amount
Yes to some extent but the correction factors will be influenced by absolute temperature levels, airflow in the room etc.
Would probably be easier in all-in-one integrated sensor and not "a bunch of separate parts" as then the temp sensor could just be near incoming air so any heating from the board would be offseted by that
Re: Air quality monitors: paying more does not get you more accuracy
#139Earlier quoted context omitted.
I can recommend Xiaomi Smart Scale 2 ( not the body composition one, it's nonsense). It is very accurate and repeatable. So much so, that you can see your weight drop after you go to the toilet. It is fascinating how much one's weight fluctuates during the day (or night which is even weirder if you don't eat/drink anything!)
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
Re: Air quality monitors: paying more does not get you more accuracy
#140Earlier 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?
Why are pharmaceutical companies allowed to sell medicine that has no improvement over placebo? See phenlyephrine which is in every single OTC decongestant/cold medication