Measurement of Resistance

Resistance is one of the most basic elements encountered in electrical and electronics engineering. The value of resistance in engineering varies from very small value like, resistance of a transformer winding, to very high values like, insulation resistance of that same transformer winding. Although a multimeter works quite well if we need a rough value … Read more

Megger | Working Principle Types History Uses of Megger

History of Megger The device is being used since 1889, popularity raised during 1920s since the long back device is same in its uses and purpose of testing, few real improvements appeared in recent years with its design and quality of tester. Now high-quality options are available which are easy to use and quite safe. … Read more

Rectifier Type Instrument | Construction Principle of Operation

Rectifier type instrument measures the alternating voltage and current with the help of rectifying elements and permanent magnet moving coil type of instruments. However the primary function of rectifier type of instruments work as voltmeter. Now one question must arises in our mind why we use rectifier type of instruments widely in the industrial world … Read more

Thermocouple Type Instruments Construction Principle of Operation

Before We introduce you about thermocouple type instrument in detail. We should first know the meaning of term thermocouple. Basically thermocouple consists of two different metals which are placed in contact with each other as shown in the diagram. First part is called the heater element because when the current will flow through this, a … Read more

Electrostatic Type Instruments Construction Principle Torque Equation

Working Principle of Electrostatic Type Instruments As the name suggests the electrostatic type instrument use static electrical field to produce the deflecting torque. These types of instrument are generally used for the measurement of high voltages but in some cases they can be used in measuring the lower voltages and powers of a given circuit. … Read more

Permanent Magnet Moving Coil (PMMC) Meter

What is a Permanent Magnet Moving Coil (PMMC)? A Permanent Magnet Moving Coil (PMMC) meter – also known as a D’Arsonval meter or galvanometer – is an instrument that allows you to measure the current through a coil by observing the coil’s angular deflection in a uniform magnetic field. A PMMC meter places a coil … Read more

Errors in Measurement | Classification of Errors

In order to understand the concept of errors in measurement, we should know the two terms that defines the error and these two terms are written below: True Value It is not possible to determine the true value of a quantity by experiment means. True value may be defined as the average value of an … Read more

Electrical Measuring Instruments | Types Accuracy Precision Resolution Speed

Basically there are three types of measuring instruments and they are Electrical measuring instruments Mechanical measuring instruments. Electronic measuring instruments. Here we are interested in electrical measuring instruments so we will discuss about them in detail. Electrical instruments measure the various electrical quantities like electrical power factor, power, voltage and current etc. All analog electrical … Read more

Induction Type Meters

The principle of working and construction of induction type meter is very simple and easy to understand that’s why these are widely used in measuring energy in domestic as well as industrial world. In all induction meters we have two fluxes which are produced by two different alternating currents on a metallic disc. Due to … Read more

Moving Iron Instrument

This instrument is one of the most primitive forms of measuring and relay instrument. Moving iron type instruments are of mainly two types. Attraction type and repulsion type instrument. Whenever a piece of iron is placed nearer to a magnet it would be attracted by the magnet. The force of this attraction depends upon the … Read more