Instrumentation is the branch of engineering that deals with measurement and control.
According to
ISA or known as
Instrumentation and Systems Automation Society formerly known as
Instrument Society of America, the
official definition of Instrumentation - is a collection of Instruments and their application for the purpose of Observation, Measurement and Control. Reference: ISA std. S 51.1 – (Instrument Society of America)
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
solenoidA solenoid is a three-dimensional coil. In physics, the term solenoid refers to a loop of wire, often wrapped around a metallic core, which produces a magnetic field when an electric current is passed through it...
s,
valveA valve is a device that regulates the flow of a fluid by opening, closing, or partially obstructing various passageways. Valves are technically pipe fittings, but are usually discussed as a separate category....
s,
circuit breakerA circuit breaker is an automatically-operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow...
s, and
relayA relay is an electrically operated switch. Electric current through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts...
s. These devices are able to change a field parameter, and
provide remote or automated control capabilities.
Transmitters are devices which produce an
analog signalAn Analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
, usually in the form of a 4–20
mAThe ampere is the SI unit of electric current. The ampere, in practice often shortened to amp, is an SI base unit, and is named after André-Marie Ampère, one of the main discoverers of electromagnetism....
electrical current signal, although many other options using
voltageVoltage is commonly used as a short name for electrical potential difference. Its corresponding SI unit is the volt...
,
frequencyFrequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency....
, or
pressurePressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
are possible. This signal can be used to control other instruments directly, or it can be sent to a
PLC-Business:* Public limited company, in the UK, Ireland and the Philippines, is a type of limited company whose shares may be sold to the public* Program length commercial, or infomercial* Product life cycle, the succession of stages a product goes through...
,
DCS-Education:*Diploma of Collegial Studies, a certificate awarded for completion of pre-university studies in the province of Québec, Canada*Dipolog Community School*Division of City Schools-Manila, a division of the Department of Education of the Philippines...
,
SCADASCADA stands for supervisory control and data acquisition. It generally refers to an industrial control system: a computer system monitoring and controlling a process...
system, or other type of computerized controller, where it can be interpreted into readable values and 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
Instrumentation can be used to measure certain field parameters (physical values):
These measured values include:
- pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
, either differential or staticIn fluid mechanics the term static pressure has several uses:* In the design and operation of aircraft, static pressure is the air pressure in the aircraft’s static pressure system....
- flow
- temperature
In physics, temperature is a physical property of a system that underlies the common notions of hot and cold; something that feels hotter generally has the higher temperature. Temperature is one of the principal parameters of thermodynamics...
- Temperature measurementTemperature measurement using modern scientific thermometers and temperature scales goes back at least as far as the early 18th century, when Gabriel Fahrenheit adapted a thermometer and a scale both developed by Ole Christensen Røemer...
- level
-Places:*Levél, a village in Hungary*Level, Ohio, a former community in the United States*Somerset Levels, a wetland area of central Somerset, England-Engineering-related:*A floor of a building or a mine...
- Level MeasurementLevel Measurement refers to instrumentation techniques designed to measure the height of a fluid or solid within a containing vessel.- Liquid/fluid measurement techniques :*Radar*Guided radar*Electromechanical*Ultrasonic*Capacitance*Hydrostatic pressure...
- density
The density of a material is defined as its mass per unit volume. The symbol of density is ρ .- Formula :Mathematically:where: is the density, is the mass, is the volume....
- viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear stress or extensional stress. In everyday terms , viscosity is "thickness." Thus, water is "thin," having a lower viscosity, while honey is "thick," having a higher viscosity...
- radiation
In physics, radiation describes any process in which energy emitted by one body travels through a medium or through space, ultimately to be absorbed by another body...
- current
- voltage
Voltage is commonly used as a short name for electrical potential difference. Its corresponding SI unit is the volt...
- inductance
Inductance is the property in an electrical circuit where a change in the electric current through that circuit induces an electromotive force that opposes the change in current ....
- capacitance
In electromagnetism and electronics, capacitance is the ability of a body to hold an electrical charge.Capacitance is also a measure of the amount of electric charge stored for a given electric potential. A common form of charge storage device is a parallel-plate capacitor...
- frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency....
- resistivity
Electrical resistivity is a measure of how strongly a material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electrical charge...
- conductivity
Conductivity may refer to:*Electrical conductivity, a measure of a material's ability to conduct an electric current*Conductivity , a measurement of an electrolytic solution, such as water...
- chemical composition
- chemical properties
- various physical properties
Control
In addition to measuring field parameters, instrumentation is also responsible for providing the ability to modify some field parameters.
Instrumentation engineering
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
chemicalA chemical plant is an industrial process plant that manufactures chemicals, usually on a large scale. The general objective of a chemical plant is to create new material wealth via the chemical or biological transformation and or separation of materials. Chemical plants use special equipment,...
or
manufacturingManufacturing is the use of machines, tools and labor to make things for use or sale. The term may refer to a range of human activity, from handicraft to high tech, but is most commonly applied to industrial production, in which raw materials are transformed into finished goods on a large scale...
plants, with the goal of improving system
productivityProductivity is a measure of output from a production process, per unit of input. For example, labor productivity is typically measured as a ratio of output per labor-hour, an input. Productivity may be conceived of as a metric of the technical or engineering efficiency of production. As such, the...
, reliability, safety, optimization and stability.
To control the parameters in a process or in a particular system Microprocessors , Micro controllers ,PLCs 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 and maintenance of 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.
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