INSTRUMENTATION & CONTROL

"Instrumentation is the branch of engineering that deals with measurement and
control."
An instrument is a device that measures or manipulates variables such as flow, temperature, level, or pressure. Instruments include many varied contrivances which can be as simple as valves and transmitters, and as complex as analyzers. Instruments often comprise control systems of varied processes. The control of processes is one of the main branches of applied instrumentation.

Control instrumentation includes devices such as solenoids, Valves, breakers, relays, etc. These devices are able to change a field parameter, and provide remote and/or automated control capabilities.

Transmitters are devices which produce an analog signal, usually in the form of a 4-20 mA electrical current signal, although many other options are possible using voltage, frequency, or pressure. This signal can be used to directly control other instruments, or sent to a PLC, DCS, SCADA system or other type of computerized controller, where it can be interpreted into readable values, or used to control other devices and processes in the system.

Instrumentation plays a significant role in both gathering information from the field and changing the field parameters, and as such are a key part of control loops.

Measurement:
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Instrumentation can be used to measure certain field parameters (physical values):

These measured values include:
pressure, either differential or static
flow
temperature - Temperature_measurement
level - Level Measurement
density
viscosity
radiation
current
voltage
inductance
capacitance
frequency
resistivity
conductivity
chemical composition
chemical properties
various physical properties

Control :
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Control valve.In addition to measuring field parameters, instrumentation is also responsible for providing the ability to modify some field parameters.

Some examples include:

Device <=====>Field Parameter(s)
1)Valve ======Flow, Pressure
2)Relay ======Voltage, Current
3)Solenoid ====Physical Location, Level
4)Circuit breaker ==Voltage, Current

Instrumentation engineering :

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Instrumentation engineering is the engineering specialization focused on the principle and operation of measuring instruments which are used in design and configuration of automated systems in electrical, pneumatic domains etc. They typically work for industries with automated processes, such as chemical or manufacturing plants, with the goal of improving system productivity, reliability, safety, optimization and stability. To control the parameters in a process or in a particular system Microprocessors , Micro controllers ,PLC's etc are used. But their ultimate aim is to control the parameters of a system.


Instrumentation technologists and mechanics :-
Instrumentation technologists, technicians and mechanics specialize in troubleshooting and repairing instruments and instrumentation systems. This trade is so intertwined with electricians, pipefitters, power engineers, and engineering companies, that one can find him/herself in extremely diverse working situations. An over-arching term, "Instrument Fitter" is often used to describe people in this field, regardless of any specialization. oo nga.