How do rain-sensing windshield wipers work?

Rain-sensing wipers use optical, infrared, or acoustic technology, or a combination of the three, to detect rainfall.

How Vehicle Rain Sensor Systems Work - www.autoaccident.com

What are the benefits of automatic rain sensing wipers? - Car services

How do Automatic Windshield Wipers Work? All About Rain Sensors in Cars

Windshield Car Rain Sensors : automatic car wiper and lighting activation

How Useful Are Automatic Rain Sensing Wipers?

Understanding Windscreen Rain Sensors - Metro Auto Glass

How do rain sensors on cars work, and why do they often set wipers at the wrong speed? - Quora

Rain sensing wiper retrofit write-up (long)

How Rain sensor works II Automatic wiper control with Rain sensor