Optical Sensors Essay

765 Words 4 Pages
Introduction-
An optical sensor is a device that converts light rays into electronic signals. It measures the physical quantity of light and translates it into a form read by the instrument.
One of the features of an optical sensor is its ability to measure the changes from one or more light beams. This change is mostly based on the alteration of the light’s intensity. Optical sensors can work either on single point method or through a distribution of points. The major importance to the proper use of an optical sensor is that it retains certain facets of measured properties. It must always remain sensitive to the property.
Optical Sensors are used in numerous research, and commercial applications such as for quality and process
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When the object is sensed, the advanced electronic circuit generates an effective output signal.
Types of optical sensors-
Generally there are three types of optical sensors:
1. Through beam sensors- This type of sensors are suitable for absolute detection of solid objects. Whenever any object passing through the light transmission path, the amount of received light by the receiver will be zero or reduced and the sensing method is interrupting the light source received by the receiver.
2. Reflective sensors- This type of sensors are suitable for color differentiation. The method of detection is based on the quantity of light that is reflected back to the receiver when light meets with an object.
3. Retro reflective sensors- A light beam from the emitter is projected towards the reflective material and then returned back to the housing (emitter and receiver are parallel to each other) where receiver detects the light. An object (or target) is detected when it breaks the light beam and causes the receivers output to switch from one voltage to another.
Fiber-optic sensors-
Optical fiber sensors consist of a light source, optical fiber, external transducer and photo detector. They sense by detecting the modulation of one or more of the optical properties of the light that is being guided inside the fiber – intensity, phase, polarization, or wavelength.
It is classified into two- Intrinsic sensors and extrinsic sensors. Extrinsic sensors are those

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