How Do Rain Sensing Wipers Work?

When you need to drive in the rain, it’s rarely a comfortable experience. The rain can practically blind your vision because of all the water that pours down onto your windshield and road spray from nearby vehicles.

What’s also annoying is that you must manually turn on your windshield wipers each time it rains. This might not seem like a big deal if you live in a location which has consistent rain like Portland or Seattle.

But if you live someplace tropical where it could rain one minute and stop raining the next minute, then you might get tired of having to keep turning the wipers on and off. This is a good reason why rain sensing or automatic windshield wipers are becoming a standard feature on many new vehicles.

Related: 5 Causes of Squeaky Wipers

How Automatic Windshield Wipers Work

rain-sensing windshield wipers

The solution to this problem is rain sensory technology. A rain sensor has the ability to detect whenever water lands on your vehicle’s windshield. It simply gets mounted next to your rearview mirror so that it is close to the windshield.

The quantity of the water is measured by detecting the level of moisture on the glass. Once the water quantity on the windshield gets to be too much, the computer will activate the windshield wipers to wipe away the water until the windshield is clear again.

This technology seems to be a popular automotive innovation that consumers like to use now. It makes the driving experience so much easier and convenient for the driver as they’re driving in the rain. Of course, if you have worn wiper blades that need replacement, rain-sensing wipers that are too sensitive may just be an annoyance rather than a convenience.

While the technology does not exist in all vehicles right now, but there’s a good chance all new vehicles will have this automatic wipers in the next few years.

Read Also: Why Does Water Leak Into My Car When It Rains?

Features of the Technology

The rain sensor depends on infrared lighting to track the level of moisture on the windshield. The computer will keep the windshield wipers deactivated as long as the infrared lighting is reflected back onto the sensor from the windshield. This can only occur if the windshield is mostly dry.

Otherwise, the infrared light won’t be able to reflect properly if there are too many water droplets in its path. This automatically tells the computer that the windshield has a lot of moisture, which then prompts the windshield wipers to be activated.

As for the speed of the windshield wipers, this will also be adjusted by the rain sensor based on how fast the moisture is building on the windshield. If the moisture is building too much and scattering the infrared lighting, then the windshield wipers will move faster.

If the moisture decreases on the windshield, then the windshield wipers will move slower. They will eventually stop moving altogether after the moisture is no longer present on the windshield.

See Also: 3 Reasons There’s Moisture in Your Headlights


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