Author: John Mulindi
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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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CAMAC (IEEE-583) Modular Instrumentation Standard
The IEEE-583, IEEE-595, and IEEE 596 CAMAC (Computer Aided Measurement and Control) standards define a hardware and data transmission system which is used to house, support and communicate with various compatible instrumentation modules. A typical CAMAC crate shown in Figure 1.0 below is a physical package which has 25 slots or powered stations for compatible,…
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Pulse Generator: Function, Operation & Applications
The Function of a Pulse Generator A pulse generator is an electronic instrument used to generate pulses for use in different types of electronic applications. Pulse generators are mainly utilized for production of pulses that are used to test applications that involve digital circuits like shift registers, counters, and so forth. Operation of the Pulse…
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Testing, Pre-commissioning & Plant Commissioning Requirements
Introduction A new installation must be fully tested to ensure that the equipment is in full working order prior to its being started. This testing is typically divided into three phases: Pre-Installation Testing This is the testing of each instrument for correct calibration and operation prior to its being installed in the field. Such testing…
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What is the Function of a Steam Desuperheater?
Whereas superheated steam offers an excellent source of energy for mechanical power generation, in most cases, steam at greatly reduced temperatures, near saturation, proves a more desirable commodity especially for most heat-transfer applications. Precise temperature control is required to enhance heating efficiency; eliminate unintentional superheat in throttling processes; or to protect the downstream product or…
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Control Valve Selection Guide
Valves are manual or automatic fluid controlling elements in a piping system; in other words, valves isolate, switch, and control fluid flow in piping systems. They are constructed to withstand specific range of temperature, pressure, corrosion, and mechanical stress. Valves can be operated manually using levers or gear operators or remotely using electric, pneumatic, electro-pneumatic…
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Volume Booster: Function, Operation & Application
Function of a Volume Booster A volume booster is a device that amplifies or boosts the volume of air supplied to the actuator, that is, it takes an input signal and produces an output of a large volume flow of air to the actuator; to be precise, a volume booster is a pneumatic device made…
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Electro-Pneumatic Valve Positioners: Function & Features
Valve positioners are motion-control devices that are made in such a way to actively compare valve stem position against the control signal, adjusting the actuator diaphragm or piston till the correct stem position is achieved, that is, in a nutshell a valve positioner’s goal is to ensure the mechanical valve’s position matches the command signal…
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Instrument Grounding: General Guidelines
Specific attention must be paid to instrument grounding, especially where field instruments are connected to a computer or microprocessor based control system. Where cable screens are used, ground continuity of screens must be maintained throughout the installation with the grounding at one point only such as that in the control room. At the field end…
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Function Generator: Features & Applications
Features of Function Generators A function generator is a signal source that can produce different types of waveforms as its output signal. The most common output waveforms are: sine waves, square waves and triangular waves. Furthermore, some function generators also produce sawtooth, pulse and non-symmetrical square waves. A typical frequency range for function generators is…