How Do Rain Sensing Wipers Work?

Rain sensing windshield wipers provide ease and convenience for the driver, especially during inconsistent weather. They automatically sense any kind of vision-impairing precipitation and adjust speed accordingly.

The Facts

A sensor mounted on either the inside or the outside of the front windshield projects infrared light, which is invisible to the human eye. The light reflects off the windshield and the sensor reads the amount of light reflected back. The more precipitation in the environment --- whether rain, snow, sleet or even dust --- the less light reaches the sensor. When this happens, the windshield wipers move faster.

Misconceptions

For the safety of both driver and the automatic wiper system, rain sensing wipers must first be activated every time the car is turned on. This prevents the wipers from turning on when the windshield is frozen, which could break the wipers. Once activated, the driver no longer has to worry about the wipers; they will start when precipitation accumulates on the windshield.

Benefits

Rain sensing wipers allow the driver to simply activate the wipers once. The driver never has to adjust the settings or speed of the wipers or turn them on and off with inconsistent precipitation. It is especially beneficial while driving through varying degrees of traffic, because the driver does not have to continually change the speed of the wipers.

References

• JDPower.com: Rain-sensing Wipers
• US Department of Transportation: Weather Applications and Products