Resistance-Temperature Convention Calculation in EPA Temperature Transducer

In the research of EPA temperature transducer, Platinum temperature-resistance is used as forward transducer input. Because standard format of R-t is a quartic equation on t when temperature is between -200 and 0 centigrade, a suitable method must be found so that we can calculate the temperature value online. On the same time, this method should be easy to realize and fit to be applied in embedded environment. So in this article, a new analytic method will be argued, which bases on the theory of quartic equation with one known and cubic equation with one known. The calculation result is compared with Newton´s method and the error is analyzed through MATLAB. It is proved that this analytic method has no model error and the time for calculating is fixed and it can also be applied in similar fields if necessary.