## Protection of Meters

When we measure an electrical signal there very often may be a chance of over current through the meter. This may be due to following reasons. The meter may be connected wrongly to the circuit. The rating of the meter is selected wrongly for the measurement. Occurrences of over current in the circuit itself during … Read more

## Varmeter | Single Phase and Polyphase Varmeter

The instruments which measure the reactive power of the circuit are called varmeter. What is reactive power? The reactive power in the circuit is given by VIsinA. Here there is no need to give an explanation about the physical meaning of reactive power, as only a mathematical relation is sufficient. Measurement of reactive power is … Read more

## Weston Type Frequency Meter

The main principle of working of weston type frequency meter is that “when an current flows through the two coils which are perpendicular to each other, due to these currents some magnetic fields will produce and thus the magnetic needle will deflects towards the stronger magnetic field showing the measurement of frequency on the meter”. … Read more

## Power Factor Meters | Electrodynamometer Type Power Factor Meter

Before we introduce various types of power factor meters it is very essential to understand what are the needs of power factor meter? Why we do not directly calculate power factor in an AC circuit just by dividing the power with product of current and voltage because these readings can be easily obtained from wattmeter, … Read more

## Phase Sequence Indicator

We have three phase system and by convention we write three phases as RYB. Phase sequence indicator is the indicator that determines the phase sequence of the three phase supply system. When we give conventional three phase supply (i.e. RYB) to the induction motor, we see that the direction of the rotation of the rotor … Read more

## Water Meter

Water meter is a type of flow meter which is used to monitor the rate of flow of water through a pipe under consideration. Types of Water Meters Water meter can be of various types depending on the place in which they are deployed. For example: Gear Type Water Flow Meter Generally, all residential water … Read more

## Vector Impedance Meter

Impedance, which is having both magnitude and phase, is truly an opponent to the flow of current in AC circuits with the presence of an applied voltage. The Vector Impedance Meter is employed for measuring both the amplitude and phase angle of impedance (Z). Normally, in other measuring techniques of impedance, the individual values of … Read more

## Ammeter Working Principle and Types of Ammeter

Introduction of Ammeter As we know a word “meter” is associated with the measurement system. Meter is an instrument which can measure a particular quantity. As we know, the unit of current is Ampere. Ammeter means Ampere-meter which measures ampere value. Ampere is the unit of current so an ammeter is a meter or an … Read more

## Electronic DC Voltmeter

The electronic voltmeters are most widely used now a day, with the advancement of semiconductor devices they are becoming increasingly popular. Now, why do we use electronic voltmeters instead we have cheap electromechanical voltmeter available?? The answer is that they posses certain advantages so that they are popular. There are many types of electronic voltmeters … Read more

## Working Principle of Voltmeter and Types of Voltmeter

What is Voltmeter? Voltmeter is a voltage meter. Which measures the voltage between the two nodes. We know the unit of potential difference is volts. So it is a measuring instrument which measures the potential difference between the two points. Working Principle of Voltmeter The main principle of voltmeter is that it must be connected … Read more