Stochastic two-bit on-line temperature measurement with RTD Pt-100 sensor operating in a nonlinear mode

Abstract

The paper proposes a method and device for on-line temperature measurement with Pt-100 sensor operating in a nonlinear mode. The sensor measures the temperature in range of 00C to 2000C, whereas the measured data are processed by applying a two-bit stochastic digital measurement method. The proposal is theoretically analyzed and tested experimentally. It is shown that the accuracy of the method depends on the accuracy of the sensor. At a sampling frequency of 1 MHz, the maximum accuracy is reached in 17.5 sec. and is equal to 0.015% of full scale (FS). On the other hand, when the measurement time interval is 0.1 sec. (the shortest measurement interval), the accuracy is equal to 0.1% of FS. Therefore, the proposed device can be used for both calibration and measurement purposes.