Automotive manufacturers are continually striving to improve and advance vehicle technologies and ensure maximum comfort, while always prioritizing safety. The anti-fogging system has proven to be a key element in this respect. A clear view is one of the most important requirements for driver safety, and integrated sensors ensure that the driver and camera systems always have an unobstructed view. By continuously measuring the temperature and relative humidity on the inside of the windshield, data is transmitted to the HVAC system. This information enables demand-based ventilation control, which actively prevents the windshield from fogging up. For optimal measurements of temperature and humidity, positioning the sensors at the lower edge of the beauty cover is recommended. Mounting the sensors deep inside the beauty cover doesn't affect the sensor's functionality but adds delay to the entire anti-fogging control loop.
Anti-fogging sensors operate based on either a direct or indirect measuring principle:
Using the direct measuring principle, the humidity/temperature sensor is located directly on the windshield and thereby measures the relative humidity directly at the windshield surface. This allows the HVAC control system to use the temperature reading as windshield temperature.
Using the indirect measuring principle, the humidity/temperature sensor is not directly connected to the windshield and therefore measures ambient relative humidity. An additional temperature sensor, which is attached directly to the windshield, is therefore required to measure the temperature of the windshield surface.
With both measurement principles, the dew point temperature is calculated from the humidity/temperature sensor reading. The dew point temperature is then compared to the temperature of the windshield surface to determine the appropriate ventilation of the windshield.
With the SAAF sensor, we offer an ideal solution for all antifogging applications. Based on the direct measurement principle, its compact form factor allows flexible placement for optimal system performance. Angled connectors enable straight-forward use without additional pigtails, ensuring easy and cost-effective mounting of the SAAF on the windshield.