Platinum thermal resistance, referred to as: platinum resistance, the resistance change with the change of temperature. It has PT100HE PT1000 series products and so on. After PT 100 indicates it in 0 ℃ resistance of 100 ohms, at 100 ℃ its resistance of about 138.5 ohms. Industrial principle of it: when PT100 him at 0 degrees Celsius for 100 ohm resistance, the resistance with temperature increases its resistance is a uniform increase.