A sensor is a device that detects and responds to some type of input from the physical environment. The input can be light, heat, motion, moisture, pressure or any number of other environmental phenomena. The output is generally a signal that is converted to a human-readable display at the sensor location or transmitted electronically over a
network for reading or further processing. Elumalai polytechnic college electronic and communication engineering students have created a mini project using sensor technology. The project was exhibited to school students at the EXPO conducted at Elumalai polytechnic college in Villupuram.
Sensors can be categorized in multiple ways. One common approach is to classify them as either active or passive. An active sensor is one that requires an external power source to be able to respond to environmental input and generate output. For example, sensors used in weather satellites often require some source of energy to provide meteorological data about the Earth's atmosphere.
A passive sensor, on the other hand, doesn't require an external power source to detect environmental input. It relies on the environment itself for its power, using sources such as light or thermal energy. A good example is the mercury-based glass thermometer. Students of Elumalai Polytechnic College have created a project involving the use of a passive sensor (PIR) passive infrared sensor.
The mini-project title is “Burglar Alarm” in which the PIR sensor is used. The purpose of the project is to sound(alert) when an obstacle crosses it, especially during the night if it is installed at home or any private place. Another way in which sensors can be classified is by whether they're analog or digital, based on the type of output the sensors produce. Analog sensors convert the environmental input into output analog signals, which are continuous and varying. digital sensors convert the environmental input into discrete digital signals that are transmitted in a binary format (1s and 0s). Digital sensors have become quite common across all industries, replacing analog sensors in many situations.
As technology develops, the use of sensors will continue to expand into every aspect of our lives. Engineers and scientists around the world will use sensors to enhance transportation systems, medical procedures, nanotechnology, mobile devices, virtual and augmented reality, and even artificial intelligence (AI). This project will be an initiative for students who may further do many more projects in sensors.