The linearisation of resistance thermometers
David R. White · Journal of Physics E Scientific Instruments · 1984
The theoretical principles and practical design for the linearisation of resistance temperature detectors (RTDs) by feedback are described. The linearisation is equivalent to driving the RTD from a voltage or current source with the correct impedance and the technique may be applied to any resistance transducer. Emphasis is placed onto the platinum resistance thermometer (PRT) and the evaluation of residual nonlinearities. The residual nonlinearity of a PRT linearised over the range -40 degrees C to 200 degrees C is less than 0.02 degrees C.