Nonlinearity compensation algorithm analysis of platinum resistor for temperature measurement
LU Sheng-wen · Transducer and Microsystem Technologies · 2009
Main reasons why nonlinear errors exist in the process of temperature measurements with platinum resistors are analyzed in accordance with the intrinsic nonlinear characteristic of platinum resistors.The principle of several nonlinear compensation algorithms,such as reverse scaling function,Newton iteration method,look-up-table method are introduced.Measuring data based on single-chip temperature measurement and control system are used as samples,and the compensation error of these algorithms is analyzed and compared with the help of MATLAB under the condition of the different curve fitting order and strategy.The results show that sub-least-squares method which is used to fit the curve of voltage varying with temperature is simple and can reduce the compensation error validly.Meanwhile,the compensation accuracy of Newton iteration method is superior to reverse scaling function and look-up-table method.