Now back to the difference of OPINION, you stated the LM335 needs to be calibrated. See my post #12 and the quote I was referring to. I think your statement is wrong. I use LM335A quite often and they are usually within 1'C accuracy. I don't care if the datasheet says 3'C because in my real world experience all the units I have used have been within 1'C and my experience tells me that they DON'T need to be recalibrated for most general uses like temperature control and/or displaying 'C with a display where the PIC adc only gives 0.5'C display resolution.
If someone needs greater than 1'C accuracy that falls under the special needs category; ie "CAN be recalibrated for better accuracy", not the global; "NEEDs to be recalibrated" category.