Author: John Mulindi
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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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Phase Locked Loop High Precision Motor Speed Control System
AC generators can be utilized in high precision control systems. The AC generator rotor is rotated by the rotating shaft (i.e. the shaft from the motor being controlled). The output AC frequency is proportional to shaft speed. Zero crossings per time interval can be counted to determine speed for a simple control system. If high…
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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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Oscilloscopes: Function, Features, Applications & Selection Guide
The Function of an Oscilloscope An oscilloscope is an electronic instrument that presents a graphical display of its input voltage as a function of time. It is important to note that oscilloscopes only measure voltages not currents or resistances however it is possible to convert quantities such as current, strain, acceleration, pressure and so forth…
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NAMUR NE 107 Standard for Modern Instrumentation Diagnostics
NAMUR NE 107 is a standard adhered to by manufacturers during the design and fabrication of instruments. NAMUR NE 107 provides status signals that communicate clear messages and remedies. These status signals or diagnostic codes are categorized into four standard icons and colors making it easier for users to comprehend them irrespective of the manufacturer…
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Steam Conditioning Valves – Features, Advantages & Applications
The Work of Steam Conditioning Valves & Why they are used in Industrial Processes Typically in an industrial set up, it may be necessary downstream of the main process application of superheated steam to reduce its pressure and temperatures to enhance the process efficiency, protect the equipment or perform other processes. This can be accomplished…
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Steam Traps – Basic Features, Types & Applications
A steam trap is a control valve whose basic function is to allow condensate to flow, while preventing the passage of steam until it has given up its heat by condensing back to water; in other words, a steam trap is a self-contained valve which automatically drains condensate and discharges air and non-condensable gases from…