说明：  PT100是铂热电阻，简称为：PT100铂电阻，它的阻值会随着温度的变化而改变。PT后的100即表示它在0℃时阻值为100欧姆，在100℃时它的阻值约为138.5欧姆。
(PT100 is platinum thermal resistance, referred to as PT100 platinum resistance. Its resistance will change with the change of temperature. 100 after PT means that it resists 100 ohms at 0 degrees, and its resistance is about 138.5 ohms at 100.)