IF you need repeatable accuracy of .1d deg F you will need to use a Platinum RTD sensor, .3 Deg can be done with a thermistor or much better an Analog Device AD592... 1 degree is easily done with an LM34/6 and 2deg is easily done with a TMP36. There are resources in the Playground referring to calibrating or 'normalizing' a thermistor's output and there is a man named Anderson, P. H. Anderson who has a website and there you will find tables of data for normalizing thermistors as well as the calculations to do so. The AD592 is probably the best device overall for accurate repeatable and reasonably priced temperature measurements. I've attached data sheets for all three.
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AD592.pdf (773 KB)
LM34_5.pdf (237 KB)
TMP35_6_7_c.pdf (366 KB)