I want to measure a very low temperature (<-50C) with an NTC thermistor, but the error in my system is dominated by my ADC frontend characteristics due to the high resistance of the thermistor (>500k). Are there any downsides to putting two NTC thermistors in parallel next to each other? Assuming that they are very close, and thermally bonded, it seems like this would decrease the resistance measurement error of my system, and not really increase the resistance error of the NTC readings at that temperature?
It seems like you could do the same thing for high temperatures, with NTCs in series?
Obviously both of these approaches have downsides in the other end of the scale (parallel is bad for high temp, series is bad for low temp). Its also possible to get thermistors with lower resistances for the low end range, although they seem to be in short supply.