The focus of this article is to define the term proximity sensor. If you are the kind that loves technology and everything that comes with it, then, you should give this article a read. A proximity sensor is an electromagnetic sensor that detects the presence of an object that falls within its predefined vicinity. Some folks in the tech community prefer to use the term as “electronic sensor.” Whichever word you decide to use is fine because both names speak of the same thing. The mere fact that it is an electromagnetic sensor implies that it does not need to have physical contact with an object before it detects its presence.
It works using the principles of electromagnetic radiation. A sensor is a small object attached to a device (mostly mobile phones) at any defined position from where it releases electromagnetic radiation. It is with this radiation that it detects an object within its predefined environ or vicinity. As the electromagnetic radiation is released, it passes through the field (space) in front of it in the bid of finding an object obstruction in its path. The kind of object you want to detect is what determines the types of proximity sensors that will be used. Once there is a change in the (electromagnetic) field in which the radiation passes through, the sensor knows that there is an object in front of it. This is why your phone goes off when your hand or finger moves over the sensor, or when you place your phone close to your ear during a phone, and it goes off. But, when you take the phone off your ear, it comes on again. Some other proximity sensors use light and sound.
The reason why your phones off is this: your phone is placed in a position that allows your ear to fall within the range of being detected by the sensor. The application of this is that it prevents accidental touching of your phone’s screen during phone calls. With this few information, you are now acquainted with proximity sensor basics. The proximity sensor has a long lifespan. Why? It does not have any form of contact with the object it senses. Where there is no contact, there is no friction; where is no friction, there is no wear and tear; and, where there is no wear and tear, there is no reduction in lifespan.
Now that the question “what is proximity sensor” has been answered, the remaining portion of this article will list the various types of proximity sensors and their usefulness. Note that some sensors are best suited for detecting a particular object than others.
Different types of Proximity Sensor
The different types of proximity sensor include-
1- Inductive Type
Best for detecting metallic objects
2- Capacitive Type
Best for detecting non-metallic (plastic) objects, but can be used for metallic purposes as well
3- Magnetic Type
Best for detecting magnets.
There are other types of proximity sensors. Examples include; photocell, radar, sonar, infrared, Doppler effect, etc.