1. Thermistor: A thermistor is a type of resistor whose resistance changes with temperature. It is mounted on the inside of the windshield, and its resistance decreases as the temperature increases. This change in resistance can be measured and used to calculate the windshield temperature.
2. Infrared sensor: An infrared sensor is a device that detects infrared radiation emitted by objects. The infrared radiation emitted by the windshield is proportional to its temperature, so the sensor can be used to measure the windshield temperature.
The thermistor method is less expensive and more common, while the infrared sensor method is more accurate.
