In addition to the properties of thermal time constant, resistance at 25 deg C, beta, self heating derating, etc., thermistors are graded as to a property called interchangability. This property describes the unit to unit variation in the R vs T characteristic. Both GE Thermometrics and US Sensor offer a range of thermistors having this property with a value of +/- 1.0, 0.5, 0.2 and 0.1 deg C. Using a single series resistor affords one the 'luxury' of using the thermistor in a resistive divider configuration to 'linearize' the output voltage vs temperature.

I was able to use a 9.09K ohm resistor in series with a USP4163 (0.2 deg) to linearize to an error of a straight line to the actual V vs T 'S-Curve' of 5 deg C over the specified range. I did not compensate for the IR drop in the lead wires. The current flowing is a couple hundred microamps when using a 5 VDC source.

Using a lookup table, the error can be dropped to within 0.5 deg C. I you wish to remove the IR drop of the lead wires, add a third wire to measure the drop and remove using an op amp compensation circuit.

Be sure to specify Teflon coated lead wires in caustic environments.

Cheers,

Bruce