Interesting device!
Using something like the Maxim part is a good idea as it has compensation and does the digital conversion for you. The AD595 may also be worth a look if you really want to use the Due ADCs.
Purely for initial testing purposes, you should be able to connect a digital multimeter and get a reading and then compare that to a reading using a Due, there may be some discrepancy as the Due's input impedance may be low enough to skew it noticeably (I haven't quite had time to understand that part of the SAM3X datasheet). The result is never going to be fantastic going straight to the Due inputs.
What temperature range are you looking at?