If you have a random thermistor (like a random Engine Coolant Temperature (ECT) sensor or a random Intake Air Temperature (IAT) sensor), you can calculate the coefficients for the Steinhart-Hart Equation, which provides excellent curve fitting, based on three meaurments: low temperature, mid-range temperature and high temperature.


Right from Wikipedia:

T low (F)		R low (Ohm)
T mid (F)		R mid (Ohm)
T high (F)		R high (Ohm)
A	B	C
C language formula:
Now, with these coefficients, you can calulatate the temperature for any given resistance: R (Ohm) Result (F) Result (C)

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Copyleft Andrey 2013


External links:
Voltage Divider calculator