Rain sensors: what is it?

Many models of modern cars are equipped with rain sensors. What it is? What are they needed for? Is this the right thing or just another trick of marketers? Let's figure it out.

Why is this necessary?

rain sensors what is it

Bad weather is a direct threat to ride comfort,health of the driver and the integrity of the car. If the ice, sleet and snow are the concerns of the respective services, then the pollution of the windshield must be understood by the owner, and as soon as possible. Previously, the driver had to perform additional actions.

In seconds, spent on turning on and offcleaning brushes, anything could happen. In addition, a person can not react quickly enough to water that pours glass. Another thing is the rain sensor, which will perform this task for you. The automated system will detect the presence of droplets on the glass, and, depending on the degree of contamination, will start the desired cleaning mode. Let us consider in more detail how this works.

How does the rain sensor work?

Let us consider in more detail what it is. The rain sensor consists of two LEDs: emitting and receiving. One emits infrared rays, and the other (sensor) fixes their refraction. The basis of the work is the principle of comparison of clean and dirty glass. What does it mean? That is, in the memory of the electronic device the refractive indices of the rays on clean and dirty glass are loaded. If the glass is detected as wet, a purification system is started. How does that happen? Depending on the amount of precipitation, a suitable intensity of purification is selected. In modern cars there can be up to 7 different modes. When the glass clears, the wipers turn off automatically.windshield with rain sensor


The rain sensor consists of two parts connected by a wire:

  1. The control unit, which gives commandsexecutive mechanism. It is here that infrared LEDs are located. It should be placed on the inside on the windshield so that it does not obstruct the driver's view. At the same time, he must be in the area of ​​work of janitors. Usually it is attached behind the rearview mirror.
  2. A relay unit that turns on and offpurification system, as well as protects the sensor from voltage fluctuations and conductive interference. It is installed in a place convenient for connection to the power grid.

The whole device does not take up much space and is compactly located in the cabin.

Advantages and disadvantages

how the rain sensor works

Advantages of the rain sensor:

  1. The driver does not need to be distracted from the road to turn on and turn off the wipers.
  2. Rapid reaction to the contamination of glass.
  3. Rain sensors have been produced since the 2000s, and allthis time with them only cars of the middle class and above were sold. Now the rain sensor has ceased to be the privilege of expensive cars. It can also be installed in budget models.
  4. It is believed that the windshield with a rain sensor is notcan be toned. But this problem was solved: manufacturers make tint films with a hole for the rain sensor. And as a whole, tinting the windscreen is not the best idea.
  5. There is another common misconception - this is that the rain sensor will not work at night. It is not true. It is not important for the infrared rays the time of day and the degree of illumination in the street.

As with any device, the rain sensor has drawbacks:

  1. The windshield must be whole and not deformed. Otherwise, the sensor will not work.
  2. Do not recognize the snowflakes on the glass until they melt.
  3. Excessive sensitivity. The sensor can trigger from one random drop of water.
  4. If the water does not fall into the wiper zone, the sensor will not work.
  5. Only the janitors are turned on, and the washing system is not. If dirt gets on the glass, it will simply be smeared.

This article describes the pros and cons of a unique device. It's up to you whether it's true that the rain sensor is not just a marketing move, but a really useful thing.

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