Precision temperature-sensing with RTD circuits application note (PDF!) from Microchip
This application note focuses on circuit solutions that use platinum RTDs in their design (see Figure 1). The linearity of the RTD will be presented along with standard formulas that can be used to improve the off-theshelf linearity of the element. For additional information concerning the thermistor temperature sensor, refer to Microchip’s AN685, “Thermistors in Single Supply Temperature Sensing Circuits” [ 7]. Finally, the signalconditioning path for the RTD system will be covered with application circuits from sensor to microcontroller.
Read more Here