Noise measurement?

[lewis]

Why not stick an RC filter at the output set to 10Hz cutoff? 100K and 100nF ought to do it (you shouldn't get any ringing with a series resistor, only if you try to directly short the output to ground with the cap which will also have no effect). Oversample and average in your micro too to overcome the ADC's acquisition noise, and bingo. You don't need massively high bandwidth for a temperature sensor.

Can you post a diagram of your front end?

[ftransform]

voltage drop is high and a 100k/100n filter does not clear up the signal very much, mostly because of the voltage drop across resistor.
had better results with the follower + 100n, similar voltage drop.