Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

What is an Ohmmeter?Ohmmeter DefinitionAn ohmmeter is defined as a device that measures electrical resistance, indicating how much a material opposes electric current.Ohmmeters typesSeries Type OhmmeterThe ohmmeter connects a battery, a series adjustable resistor, and a meter for readings. The resistance to be measured is connected at terminal OB. When the circuit is completed, current flows, and the meter shows the deflection.When the resistance to be measured is very high then the current in t

What is Analog Multimeters?Analog Multimeter DefinitionAn analog multimeter is a device used to measure electrical quantities like voltage, current, and resistance using a needle and scale.Working PrincipleIt works on the d’Arsonval galvanometer principle. A needle indicates the measured value on a scale. When current passes through a coil in a magnetic field, it creates a deflecting torque that moves the needle over a graduated scale.A pair of hairsprings is attached to the moving spindle to pr

What is the Vector Impedance Meter ?Vector Impedance Meter DefinitionA vector impedance meter is defined as a device that measures both the amplitude and phase angle of impedance in AC circuits.Measuring Amplitude and Phase AngleIt determines the impedance in polar form by evaluating the voltage drops across resistors and unknown impedances.Equal Deflection MethodThis method ensures equal voltage drops across a variable resistor and the unknown impedance to find the impedance value.Two resistors

What is the Meters Protection ?Meter Protection DefinitionMeter protection is defined as measures taken to safeguard electrical meters from damage due to overcurrent.Overcurrent CausesOvercurrent can occur due to incorrect connections, wrong meter ratings, or unexpected circuit conditions.Single Diode ProtectionA single diode can protect a meter by short-circuiting and diverting excess current when voltage exceeds a certain limitDouble Diode ProtectionUsing two diodes in opposite directions prot

What is a Phase Sequence Indicator?Phase Sequence Indicator DefinitionA phase sequence indicator is a device used to determine the phase order of a three-phase electrical supply.Types of IndicatorsThere are two types—rotating type and static type, each with a distinct working principle.Rotating Type Working PrincipleIt works on the principle of induction motors. In this coils are connected in star form and the supply is given from three terminal marked as RYB as shown in the figure. When supply

What are the Power Factor Meters?Power factor meter definitionPower factor meters are devices used to accurately measure the power factor in AC circuits and are essential for industrial applications.Type of electric dynamometerThis type of meter measures the power factor by using two coils (a resistance coil and an inductor coil) to determine the phase difference between voltage and current.Now the pressure coil is divided into two parts, one part is pure induction, the other part is pure resist

Weston Frequency Meter DefinitionThe Weston frequency meter measures frequency by using the deflection of a magnetic needle caused by perpendicular currents in two coils.ConstructionIt includes two coils, three inductors, and two resistors arranged in a specific configuration.Circuit DiagramThe diagram shows Coil 1with a series resistor (R1) and reactance coil (L1), and Coil 2 with a series reactance coil (L2) and parallel resistor (R2).Working PrincipleAxis of both coils are marked as shown. Sc

What is an Electronic DC Voltmeter?Electronic DC Voltmeter DefinitionAn electronic DC voltmeter is defined as a device that measures direct current (DC) voltage across any two points in an electric circuit using semiconductor components.DC VoltageDC voltage is a constant voltage from sources like batteries and solar cells, with no change in polarity or magnitude over time.Working PrincipleElectronic DC voltmeters convert DC voltage to a proportional current displayed by a meter, using components

What is an Air Flow Meter Sensor?Air Flow Meter DefinitionAn air flow meter is defined as a device that measures the rate of air flow in a duct or pipe. The rate of airflow is also known as the velocity or volume of air. Air flow meters can also measure the pressure and direction of airflow, which are important parameters for some applications.Air flow meters sense air movement using various principles and convert it into an electrical signal. This signal can be displayed, recorded, or sent to a

What is Moving Iron Instrument?Moving Iron Instrument DefinitionA moving iron instrument is a type of measuring device that uses the magnetic properties of iron to measure electrical quantities.Types of Moving Iron InstrumentsThere are two main types, attraction and repulsion, which function based on the magnetic interactions of iron pieces with a magnetic field.Construction of Moving Iron InstrumentThe basic construction of attraction type moving iron instrument is illustrated bellowA thin disc