You would need identical resistors to make this work (impossible) or at least know precisely their resistance and thermal coefficients (expensive).
Extending and correcting what Kleinstein has said above about noise:
If the number of the meters/ADCs needed would increase quadratically, the situation would still be quite optimistic. Unfortunately it is increasing
exponentially. What’s the difference? See the attachment.
![Scared :scared:](https://www.eevblog.com/forum/Smileys/default/scared.gif.pagespeed.ce.oZptHNcbsD.gif)
To extend the resolution by 1 decimal digit, you would need at least 16 DMMs (not 10, because you can’t extract fractional bits). And this is resolution, not accuracy. This is why flash ADC is not used in any higher-resolution converter: for a 24-bit ADC you would need 16.7 million comparators in a chip. Oh, and a 16.7-million-lines-to-24-lines priority encoder.
![Wink ;)](https://www.eevblog.com/forum/Smileys/default/xwink.gif.pagespeed.ic.cldandycH0.png)
However, for constant voltage you may spread your measurements not in space, but in time. As long as the signal is stable (ignoring noise), 16 consecutive measurements will give you 1 more digit of resolution. Assuming infinitely high precision or precision being affected only by random noise
![Cheesy :D](https://www.eevblog.com/forum/Smileys/default/xcheesy.gif.pagespeed.ic.KPzuH4J-TG.png)
. And of course accuracy is as bad as it was. But yes, this works as a way of fighting noise.