Thanks DrMemory, I suspected as much, but could not find any info to that effect.
Otherwise, I've always suspected that a 4 wire pRTD would more than likely be my best/only choice, for reducing the noise, short of working with candlelight... (which is still not out!) but again, I can find no info about the actual resolution that I might be able to extract from an RTD probe or element.
Again, I'm not looking to measure an absolute temperature, just a temperature differential. I fully realize that I have no hope of getting to an absolute reading with a resolution of 0.001 deg C, at least not without spending an insane amount of money.
I'm not looking to use the full bit range of the 24 bit ADC, just enough to be able to pick up the differential temperature between two probes with a resolution of 0.001 deg C. The temp range would be between 20 and 50 deg C. (differential would be water temp to heat die temp, maybe 20 deg C max?) Incoherent's 0.002 (18 bit) is the closest suggestion I've seen yet.
Does anyone (other than M. Grumpy
) have a feel about if this can be done, say with 2 * pRTD 4-wire probes?