Indeed I 'plugged' no numbers into the thread knowing that until there were more than generalizations the data would get in the way...
@DaveX an interesting scenario... The worst you could dream up?... The data sheet I referenced has CC diodes from 35uA to 5.7 mA... I posted it for this diode... Not for the part itself because it's unlikely that the part is available but the basic theory is still around and the methods with it. No, for the data to point out something of passing concern
TEMPERATURE
PART # MIN NOM MAX MIN MIN MAX CO-EFFICENT
CCL0750 0.600 0.760 0.920 1.0 0.2 1.4 0.0 TO -0.32
and it's effects both on the resistors as well as the accuracy of the excitation or bias supply for the thermistor. Finally to do a thermometer of even 1/2% accuracy would be a challenge because the Arduino's Vref sources are somewhat less than 'stellar' I'd make my own first, thus the initial comment about the TIL431.. It's temperature stability is fair to good and with good design can be better, certainly better than either the 'normal' ratiometric A/D measurement or using the largely uncalibrated internal reference. All of this discussion is rather pointless because of the basic limitation of 10 bits and with oversampling, a little noise and some decimation can produce 12 bits of equivalent accuracy... But why when really cheap devices are available that essentially 'bolt' on to the Arduino with uVolt accuracy where the Uno for example is capable of a millivolt/bit resolution but at what temp and under what conditions? of noise or supply voltage and noise flowing in the grounds... One, or two grounds for Everything off board was the reason for my seemingly off the wall comment about star grounding methods.
Even after all is said there is no device that can be all to everyone and before this discussion is put to bed... where it sorely needs to be..
Is that the Arduino was intended as a teaching machine. That it does as much as it does is testimony to a good design.. To do as much as it does as well as it does and for as little as it cost's to get one working... I make Rolls Royce breadboards... I buy the little '328 stickers from Adafruit... They look "Cute"... and I can never remember what pin does what and my uno's are lost somewhere.
I'm also happily retired, this is my plan to keep sane and active as I grow daily more senile and I hang out here and once in a while make a fool of myself as well.
Doc