Basic terms commonly used in instrumentation and its definition

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INSTRUMENTATION:

A complete set of instruments combinedly used to control a process like production, refining.

INSTRUMENTS:

Devices that are used for measuring, indicating, controlling, recording can be considered as an instrument

TRANSDUCERS:

A device coverts physical quantity into an electrical quantity. Transducers are also known as Pick-Ups

CALIBRATION:

Calibration is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy.

CONTROLLER:

A device in control loop which regulates the error signals to the zero or devices which regulate the behaviour of other devices or process variable.

TRANSMISSION:

A method of sending data between various instruments of a plant in a standardized form.

TRANSMITTER:

A device which converts measurement value into a standard signal.

PROCESS VARIABLE:

The process variable is the measured value of ongoing part of a process being monitored or controlled.

SET-POINT:

The desired value required by the operator of an essential variable of a system.

ACCURACY:

Accuracy is the conformity of an indicated value to an accepted standard value or it is the limit of error can be made by an instrument in normal operating conditions.

SPAN:

Algebraic difference between the possible upper range value and lower range value