Have you ever wondered how do the doors to the hypermarkets automatically open when you stand in front of it?
The answer to all these questions will reach to a technology product; that is SENSOR. The sensors are great technological innovations to save electrical energy. They play a vital role in home security systems. The automatic doors, touch-less bathroom water pipes etc. operate with the help of these sensors. These sensors operate on the signals they are getting after sensing the different type of factors such as motion, light, weight or even sound sometimes. This article is all about presence sensing technology.
MOTION SENSORS & APPLICATIONS
Motion detecting system employs motion sensors. They work with infrared waves as well as in waves. The motion sensors are broadly classified into two; active and passive motion sensor.
Active motion sensors
Active motion sensors continuously send ultrasonic sound waves into their detection path unless and until they are disrupted by an external signal such as an arrival of a person in the detection area. This external signal triggers the sensor to send a signal to the alarming system. This alarming system will be connected to an automated door, or sometimes to a sounding alarm unit; that depends upon the area of application of these sensors.
Passive motion sensors
Passive motion sensors work with infrared energy. The energy rise in the infrared waves emitted by the passive sensors makes them operate the alarming section. The heat energy emitted by the humans and animals change the energy level of the infrared waves emitted by the passive motion sensors. These sensors only trigger the alarming section when the energy goes above a certain tolerance level.
Passive sensors can also work with light rays. A change in light intensity emitted by the sensors makes it operate the control box signals such as turning on lights or alarming bells. All these motion sensors can contribute much to the home security systems.
PRESENCE SENSORS & APPLICATIONS
The operating principle of presence detector is same as the motion detector. The operation of these detectors is based on the thermal energy emitted by them into the detection area. Any change in the thermal energy would make the alarming lights to be switched on. The presence detectors can be installed on the ceiling or on the wall.They are ideally suitable for their use in public buildings.
Sensitivity is the key factor between these sensors. Presence sensors have more sensitivity than motion sensors. They tend to detect even small changes in movements. Building automation system usually employs these sensors in their applications. PLC and SCADA programming software are widely used in the engineering field for these automation controls. Security, as well as cost-effective energy savings, can be achieved by employing any of these sensors as a part of our living.
