Tag: Sensors
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How Interferometers are used as Position Sensors
Interferometer sensors employ energy in the form of light or sound to make precise position/location measurements. There are a number of applications where accurate measurement of very small linear mechanical displacements and distances between objects in the order of nanometers is required, for instances the measurement of deflections of diaphragms and cantilevers in force, acceleration…
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Principle of Operation of Magnetostrictive Position Sensors
Magnetostrictive sensors detect the location of a magnetic ring that slides along a conductive metal tube; in other words this sensor operation utilizes the effect of a magnetic field on magnetostrictive wire to function. The figure below illustrates a Magnetostrictive position sensor: To detect the position of the magnet (in this case, an electromagnetic created…
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How to Connect Discrete Sensors to PLC Inputs
Discrete Sensor Outputs Basically sensor outputs can be categorized into two types: discrete also referred to discrete or logic and proportional also called analog. Discrete sensors supply a single logical output (1 or 0) e.g. a flow switch used to detect the fluid flow through a pipe whereas proportional/analog sensors provide an analog electronic…
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Photoelectric Pressure Transducer Operation
The photoelectric pressure transducer uses a phototube and a light source (either a stable source of light or ac modulated light) separated by a window, whose aperture is controlled by the force summing device of the pressure transducer as illustrated in the figure below: The displacement of the force summing device modulates the quantity of…
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Electronic IC Temperature Sensors
Electronic IC temperature sensors are specialized integrated circuits that are used for sensing temperatures in the -55° C to +150°C range. Basic Principle of IC Temperature Sensors The working principle of IC temperature sensors is based on semiconductor physics. When the temperature of a p-n semiconductor junction changes, the mobility of the charge carriers in…
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What is Calibration of the Sensor?
Calibration of the sensor is the relationship between the physical measurement variable input and the signal variable output for that specific sensor. Typically, a sensor or an entire instrument system is calibrated by providing a known physical input to the system and recording the output. The data is plotted on a calibration curve such as…
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Types of Load Cells and How Do They Work?
In the vast landscape of industrial measurement, load cells play a pivotal role in ensuring the accuracy and reliability of weight and force measurements. These sophisticated devices, integral to myriad applications across industries, convert mechanical force into measurable electrical outputs. Australia, with its robust and diverse industrial sector, is home to a significant demand for…
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The Principle of Operation of an Induction Potentiometer
An induction potentiometer is a rotary type linear-variable inductor with two concentrated windings wound on the stator and on the rotor as illustrated in the figure below: The rotor windings are excited with an AC, inducing voltage in the stator windings. The amplitude of the output is dependent on mutual inductance between the two coils,…
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The Principle of Piezoelectric Sensing
The piezoelectric transduction is based on the conversion of mechanical vibrations into electrical signals and vice versa. The piezoelectric effect involves the generation of electric charge by a material when subjected to a mechanical deformation. The redistribution of electrical charges in the piezoelectric material causes variations of the electric field inside the material. The reverse…
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Passive vs. Active Sensors
Sensors are normally used to convert physical variables like pressure to signal variables. Sensors are also often termed to as transducers since they are devices that convert input energy of one form into output energy of another form. Sensors can be classified into two broad classes depending on how they interact with the environment they…