Measurements and Instrumentations

Measurement and Instrumentation Image

What is measurement?

Measurement is essentially the act or the result, of a quantitative comparison between a given quantity and and a quantity of the same kind chosen as a standard or a unit. 

What is instrumentation?  

Instrumentation refers to the art and science of collection of several instruments and auxiliary equipment  and their utilisation for conducting successfully a test or an experiment on a system, process or plant.

The device used for comparing the unknown quantity with the unit of measurement or a standard quantity is called measuring instrument and the quantity to be measured is called measurand.

In electrical engineering the term measurement and instrumentation refers to the measurement of various physical quantities (solid, liquid or gaseous) and calibration of various electrical, mechanical and electromechanical parameters/systems which directly or indirectly affect the working of various electrical or electromechanical equipment. In the beginning the terms "mensuration" was used instead of measurements. The metrology is a term used to refer to the study of measurements. These measurements or estimations of physical values can not be accurate. It always bears some chances of errors. These errors in measurements are normally distributed about the actual measurement. Thus, each measurement can be described as containing three components as; an estimated value, an error bound, and the probability of finding the actual measurement within the range of error bounds of that estimated measurement.
The example of electrical parameter measuring instrument is multimeter. A multimeter measures the Current, Voltage and Resistance of the system which it is connected to.
Digital Multimeter Image
Digital Multimeter
Photo Credit - http://www.rapidonline.com/

The process of measurement is basically dependent upon the specification of standard quantities or units. These units have almost been for each physical quantity. For instance the standard unit of length is meter. There is a standard system of base units from which we can derive many other units. These derived units are also used similarly for measurements.There are many systems of units in use like; imperial system,metric system and SI system of units.

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