Differential Voltmeter

Definition: The voltmeter which measures the difference between the known and the unknown voltage source is known as the differential voltmeter. It works on the principle of comparison between the reference and the unknown voltage sources. The accuracy of the differential voltmeter is very high.The principle of operation of the differential voltmeter is similar to…

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Rectifier Type Instrument

Definition: The instrument which uses the rectifying element for measuring the voltage and current is known as the rectifying instruments. The rectifying element converts the alternating current to the direct current which indicates by the DC responsive meter. The PMMC uses as an indicating instrument. The sensitivity of the rectifying instruments is high as compared…

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Classification of Measuring Instruments

The instrument used for measuring the physical and electrical quantities is known as the measuring instrument. The term measurement means the comparison between the two quantities of the same unit. The magnitude of one of the quantity is unknown, and it is compared with the predefined value. The result of the comparison obtained regarding numerical…

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Electrodynamometer Wattmeter

Definition: The instrument whose working depends on the reaction between the magnetic field of moving and fixed coils is known as the Electrodynamo-meter Wattmeter. It uses for measuring the power of both the AC and DC circuits. The working principle of the Electrodynamometer Wattmeter is very simple and easy. Their working depends on the theory…

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Ballistic Galvanometer

Definition: The galvanometer which is used for estimating the quantity of charge flow through it is called the ballistic galvanometer. The working principle of the ballistic galvanometer is very simple. It depends on the deflection of the coil which is directly proportional to the charge passes through it. The galvanometer measures the majority of the charge…

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Ammeter Shunt

Definition: The ammeter shunt is the device which provides the low resistance path to the flow of current. It connects in parallel with the ammeter. In some of the ammeter, the shunt is inbuilt inside the instrument while in others it is externally connected to the circuit. Why Shunt Connect in parallel with Ammeter? The ammeter designs…

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Volt-Ratio Box

Definition: The volt-ratio box measures the high voltage. The construction of the volt-ratio box is very simple. It consists the simple resistive potential divider which has many tapping on the input side. The whole arrangement of the volt-ratio box is placed inside the wooden box. The volt-ratio box gives the accurate result of measure voltage.…

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Earth Tester

Definition: The instrument used for measuring the resistance of the earth is known as earth tester. All the equipment of the power system is connected to the earth through the earth electrode. The earth protects the equipment and personnel from the fault current. The resistance of the earth is very low. The fault current through…

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Synchro

Definition: The Synchro is a type of transducer which transforms the angular position of the shaft into an electric signal. It is used as an error detector and as a rotary position sensor. The error occurs in the system because of the misalignment of the shaft. The transmitter and the control transformer are the two main…

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Q Meter

Definition: The instrument which measures the storage factor or quality factor of the electrical circuit at radio frequencies, such type of device is known as the Q-meter. The quality factor is one of the parameters of the oscillatory system, which shows the relation between the storage and dissipated energy. The Q meter measures the quality…

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