Instrumentation

Instrumentation is an electrical device placed in the field to provide measurement and/or control capabilities for the system.

The simplest measurement instrumentation device is a thermistor. A thermistor is very similar to a typical resistor, except that it greatly varies its resistance depending on its temperature. Therefore this device can easily be used for measurement of temperature in the field.

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

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 is sometimes responsible to measure certain field parameters (physical values).

These measured values include:

pressure
flow
temperature
level
density
viscosity
radiation
current
voltage
inductance
capacitance
frequency
resistivity
conductivity
chemical composition
chemical properties
various physical properties
etc.

Control

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

Some examples include:

Device	Field Parameter(s)
Valve	Flow, Pressure
Relay	Voltage, Current
Solenoid	Physical Location, Level
Circuit breaker	Voltage, Current

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. 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.

Instrumentation technologists and mechanics

Instrumentation technologists, technicians and mechanics specialize in troubleshooting and repairing instruments and instrumentation systems. Installation, on the other hand, is normally performed by industrial electricians. This trade is so intertwined with electricians, pipefitters, power engineers, and engineering companies, that one can find him/herself in extremely diverse working situations.

External links

Instrumentation Society of America, see Instrumentation Society of America for more information.
Instrumentation and Control Devices - Engineers Edge