Tag: Process instrumentation
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How to Size a Control Valve
Pneumatic control valve Control valve sizing refers to the procedure determining the correct size of a valve body. A valve sizing equation for incompressible fluids is given by: Which is the same as: Where Cv is the valve flow … Read more
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Process Control System Design for a Distillation Unit
The aim of a typical control system is to force a given set of process variables to act in some desired and prescribed way by either fulfilling some requirements of the time or frequency domain or achieving the best performances … Read more
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Standard Process Signals for Industrial Instrumentation
Industrial measurement and control processes employ standard process signals that are used throughout all the industries. For instance, one of the most popular forms of signal transmission in modern industrial instrumentation systems is the 4-20 mA DC standard. The … Read more
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How the Wiegand Effect is used in Sensing Instruments
The Concept behind Wiegand Effect Based Sensors The Wiegand effect technology employs the unique magnetic properties of specially processed, small-diameter ferromagnetic wire. By causing the magnetic field of this wire to abruptly reverse, a sharp, uniform voltage is generated. … Read more
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Piezoelectric Accelerometer: Principle of Operation & Applications
An accelerometer is a sensor that is designed to measure acceleration or rate of change of speed due to motion, vibration e.g. from rotating equipment and impact events such as the deployment of an automobile airbag. Accelerometers are usually mechanically … Read more
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Steam Sampling for Conductivity: Instrumentation Structure
Sampling Systems The Purpose of Sampling Systems The objective of a sampling system is to obtain a truly sample of the solid, liquid or gas to be analyzed, at an adequate and steady rate, and transport it without change to … Read more
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Cable Screens: Types & Connections
Electromagnetic Compatibility (EMC) is one of the key factors of consideration in the design, construction, manufacture and installation of electrical and electronic equipment and systems. Electrical equipment must be designed not only to meet a functional technical performance specification but … Read more
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Instrumentation Systems Installation: Precautions to Take
Analog systems are normally based on low voltages and as a result, they are vulnerable to electrical noise. In most plants, a PLC may be controlling 415 V high power motors at 100 A, and at the same time, … Read more
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Basic Facts about 4-20 mA current loop in Process Instrumentation
The 4-20 mA current loop, like the one shown in the diagram below is a typical way of transmitting sensor information in most of industrial process monitoring applications. Figure 1.0: typical components used in a loop powered application. A sensor… Read more
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Causes of Ground Loops in Instrumentation & How to Avoid Them
Causes of Ground Loops In Instrumentation We may have situations in instrumentation and control systems, where the sensor and the signal conditioning unit such as an amplifier or current-to-voltage converter are located some distance apart and are connected by a … Read more