Measuring Instruments

Hi friends, In this article, I am going to describe the megger earth tester working principle and method of earth resistance measurement by it. I hope you will find it informative and helpful. The Resistance of the earth can be measured with the help of megger earth tester or earth megger. Megger Earth Tester Working Principle | […]

Hi friends, In this article, I am going to discuss the hand-operated megger working principle, and I will give you some important information about it. So keep reading. Insulation of any electrical machine is a very important part of the machine. Many times, machines fail due to the failure of insulation. Therefore, it is very

An analog multimeter is the most commonly used instrument by technicians and engineers in the laboratory, as well as other repair works. As it is clear from the name of this instrument, it can make many (multi) measurements with reasonable accuracies such as AC and DC voltages, currents, and resistances. Since it is a milliammeter,

A dynamometer type wattmeter is basically a moving coil instrument. But in this case, the operating field is produced by the fixed coil instead of a permanent magnet. A wattmeter in which fixed coils produce the operating field is known as a dynamometer type wattmeter. The dynamometer type wattmeters are very significant because we use

There is no fundamental difference between the operating principles of ammeters and voltmeters. Both are current-operated devices (except electrostatic type voltmeters) i.e. deflecting torque is produced when current flows through their operating coils. In an ammeter, the deflecting torque is produced by the current to be measured or by a definite fraction of it whereas

Moving Coil Instrument Working Principle  A moving coil meter is a very commonly used form of an analog instrument because of its sensitivity, accuracy, and linear scale, although it only responds to d.c. signals.  The simple view of the construction of the moving coil instrument is shown in the figure. It consists of a powerful

The moving iron instruments or MI instruments are quite cheap in cost, simple in construction and very accurate at fixed power supply frequency. These instruments can be used on AC as well as DC. Therefore, these are widely used in laboratories and on switching panels. These instruments are used either as ammeters or voltmeters only.

In order to ensure proper operation of indicating instruments, the following three torques are required: Deflecting Torque | Controlling Torque | Damping Torque  One important requirement in indicating instruments is the arrangement for producing operating or deflecting torque (Td) when the instrument is connected in the circuit to measure the given electrical quantity. This is achieved