Tag: Process instrumentation
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Telemetry in Instrumentation Systems
Telemetry can be defined as the science of gathering information at some remote location and transmitting the data to a convenient location to be examined and recorded. Importance of Telemetry Within instrumentation there is usually a requirement for telemetry in … Read more
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How Capacitive Probes are Used to Measure Level
Capacitive probes can be used to measure the depth of liquids and solids. A rod, normally coated with PVC or PTFE, is inserted into the tank and the capacitance measured to the tank wall. The capacitance has two components C… Read more
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PFDs vs. P&IDs
Process Flow Diagrams (PFDs) defines the major elements of the process schematically i.e. the interconnections of process vessels, pipes and flow paths of process fluids. On the other hand, Piping and Instrument Diagrams (P&IDs) shows the layout of all relevant … Read more
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Process Instrumentation Diagnostics & Communication Interfaces
There are various technologies that are available that help plant automation personnel to obtain diagnostic data which inform the type of maintenance to be undertaken. For example, using Distributed Control System (DCS), PC software tools, or handheld communicators, plant … Read more
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How a Bubbler Device is used for Level Measurement
An often utilized technique of indirectly measuring a liquid level is to measure the hydrostatic pressure at the bottom of the container. The level can then be extrapolated from the pressure and the specific weight of the liquid. This is … Read more
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Sources of Coherent Interference/Noise in Instrumentation Systems
Introduction The knowledge of how to design low noise instrumentation systems is an essential skill that any practicing instrumentation engineer should strive to learn because noise and interference affects any measurement system in one way or the other and this … Read more
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Fiber Optic Temperature Sensors: Principle of Operation & Applications
As the name suggests these sensors employs fiber optics technology to function. A fiber optic sensor generally guides light to and from a measurement zone where the light is modulated by the measurand of interest and returned along the same … Read more
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Radar Level Transmitters: Operating Principle & Applications
Radar level transmitter basically employs electromagnetic waves to determine the fluid level in a tank. It converts level information into a 4-20 mA signal and transmits it to the controller; this signal may then be used in a measurement … Read more
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Pneumatic Signal Transmission System
Signal transmission in process instrumentation and control systems is largely done via electrical transmission but there are a few areas where pneumatic transmission of signals is vital especially where electrical signals or sparks can ignite combustible materials for example in … Read more
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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 … Read more