PT100温度传感器高精度计算方法，不需要查表，直接计算出结果，简化代码-PT100 temperature sensor precision calculation method, don t need a look-up table, calculated results directly, simplify the code

计算热敏电阻与温度对照表,通过给定的温度和阻值计算B值.(Calculate the look-up table and the B value of the thermistor)