Dynamic Compensation of Pt100 Temperature Sensor in Petroleum Products Testing Based on a Third Order Model

In this paper, taking example for closed cup flash point testing, a 3rd order model is presented to describe the dynamic characteristic of sheathed Pt100 sensor for the first time, to solve the problem that there are dynamic characteristic discriminations between the Pt100 temperature sensor and the mercury thermometer, which bring errors to measuring. The mathematical models of sheathed Pt100 sensor and mercury thermometer are analyzed, and their transfer functions are evaluated, via step response experiments, assisted with calculation and simulation using MATLAB software. A compensation algorithm based on transfer functions is presented. Experimental results show that the algorithm can get better compensation effect than the traditional method which compensate with a selected static temperature curve, and also can be used in temperature measurement systems in which dynamic characteristic of sensors are definitely required.