The Pt100 temperature sensor is an instrument that converts a temperature variable into a transmittable, standardized output signal. Pt100 is a platinum thermal resistor, and its resistance will change with temperature. 100 after Pt means that its resistance value is 100 ohms at 0°C, and its resistance value is about 138.5 ohms at 100°C. Mainly used for the measurement and control of industrial process temperature parameters. Its working principle is that when the PT100 is at 0 degrees Celsius, its resistance value is 100 ohms, and its resistance value will increase approximately uniformly as the temperature rises. But the relationship between them is not a simple proportional relationship, but should be closer to a parabola.