Advantages of Rain sensor | Disadvantages of Rain sensor

This page covers advantages and disadvantages of Rain sensor. It mentions Rain sensor advantages and Rain sensor disadvantages.

Definition: The sensing device which detects the fall of rain and acts accordingly is known as rain sensor. It has wide variety of applications including turning off an irrigation system, automatic wiper system in car etc.

Rain sensor turns off irrigation system within minutes when rain falls. Here it consists of water absorbing expansion disks which swell in presence of rain drops. After some amount of rain falls, electrical switch gets depressed. As a result, regular cycle of irrigation is bypassed and automatic irrigation system is switched off. Disks shrink when dry condition is reached and reverse action takes place.

Rain Sensor Principle

The figure-1 depicts principle of rain sensor in automatic wiper system. As shown, light emitted by LED is received by silicon photodiode. When no rain falls, light intensity of the beam will remain constant at photodiode. When rain drops fall, light intensity changes according to size and number of rain drops. In car circuit, rain sensor is monitored by micro-controller circuit which drives the wiper switch and wiper motor to control the wiper. It is also used for rain water harvesting system which collects rain and later use it for home, garden etc.

Advantages of Rain sensor

Following are the advantages of Rain sensor :
➨It helps in saving money by switching off the irrigation system when it rains. This saves money by cutting off bills on electricity consumption.
➨It extends life of rain sensor based systems such as car wiper, irrigation systems by running them only when it is necessary.
➨Rain sensors help save water during rain events and hence water is available during summer and emergency applications such as firefighting etc.
➨Operating principle is very easy.
➨It consumes less power for operation.
➨Installation of rain sensor based systems are very much simple.
➨Individual rain sensor costs very less.

Disadvantages of Rain sensor

Following are the disadvantages of Rain sensor :
➨The rain sensor based system functions when water falls on the sensor directly.
➨The cost of overall system increases as additional components are needed along with rain sensor.
➨In order to avoid false detection of rain, it requires rain sensors to take decision after few minutes.

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