INTRODUCTION & TYPES OF ELECTRICAL INSTRUMENTS

INTRODUCTION & TYPES OF ELECTRICAL INSTRUMENTS

In this article we will study about ELECTRICAL INSTRUMENTS.

So starting from basics, question arises what are electrical instruments?

Any instrument which is used to measure electrical quantities like current , voltage , electrical power , electrical energy , power factor , frequency etc. are called ELECTRICAL INSTRUMENTS.

Now we will move on to the classification of electrical instruments.

CLASSIFICATION OF ELECTRICAL INSTRUMENTS.

There are many ways in which electrical instruments can be classified.

Like Electrical Instrument can be classifies as

1. Absolute Instruments :– These instruments, which gives the value of the quantity to be measured in terms of the constant of the instrument.

Example – tangent galvanometer , Raleigh’s Current Balance etc.

2. Secondary Instruments :- These instruments gives the magnitude of the quantity directly by the deflection of pointer on the scale.

Examples – voltmeter , Ammeter etc.

Mostly, now Secondary Instruments are used.

Electrical Instruments are also classified as-

1. Analog Instruments :-  Such instruments have a calibrated scale and a pointer. Pointer moves on the scale and thus gives the reading of the quantity.

2. Digital Instruments :- These instruments does not consists of scale or pointer, they directly gives the reading in the digital form.

There is another a most popular way of classifying the Electrical Instruments

1. Indicating Instruments :-  These instruments indicates the instantaneous value of the quantity under measurement.

Their indication is given by the pointers moving over calibrated scales.

Ordinary Ammeter and Voltmeter comes in this category.

2. Recording Instruments :-  Those instruments which gives the continuous record or variation of the quantity under measurement over a period of time.

Such Instruments consists of inked pen which moves on the chart or graph. The path traced by the pen represents the continuous record of the variation of quantity.

Eg:- ECG, a machine used by doctors to record heart beat.

3. Integrating Instruments :- These instruments neither provide instantaneous value nor they maintain record of the quantity, but they integrate or sums up the quantity under measurement.

Example of such instruments are ampere hour meter, energy meter etc.

Energy Meter goes on integrating the units being consumed and reads the total sum of the units consumed since beginning.