Essay On Proximity Sensor

A sensor that can be able to detect the presence of nearby objects without any sort of physical contact is called as proximity sensor. This sensor emits an electromagnetic field or a beam of electromagnetic radiation and looks for the return signal or any changes in the field. The object being sensed is referred to as target of the proximity sensor. Different proximity sensor targets require different sensors. For example, for a plastic target an capacitive or photoelectric sensor might be suitable; an inductive proximity sensor always requires a metal target. The maximum distance that can be detected by the sensor is known as "nominal range". Some of these sensors that have adjustments to the nominal range or means to report a graduated detection distance. This is known as "thermosensation".

Sensors which are generally used in detecting ferrous targets, ideally mild steel thicker than one millimeter are called inductive or non-contact proximity sensors. They contain four components: a

Identifying their output is thus made easy; light-on and dark on light-on classifications which might refer to light reception and sensor output activity. If output is produced when no light is received, the sensor is dark-on. Output from light received, and its light-on. Either way, deciding on light-on or dark-on prior to purchasing is required unless the sensor is user adjustable. (In that case, output style can be specified during installation by flipping a switch or wiring the sensor accordingly.)
Ultrasonic proximity sensors are used in many automated production processes. They employ sound waves to detect objects, so color and transparency do not affect them (though extreme textures might). This makes them ideal for a variety of applications, including the long-range detection of clear glass and plastic, distance measurement, continuous fluid and granulate level control, and paper, sheet metal, and wood