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

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

What are Electrostatic Type Instruments?Electrostatic Instrument DefinitionAn electrostatic instrument is defined as a device that uses static electrical fields to measure voltage, usually high voltages.Working PrincipleAs the name suggests, electrostatic instruments use static electrical field to produce deflecting torque. They are typically used to measure high voltages but can also measure lower voltages and power in some cases. There are two ways the electrostatic force can act.Construction

PMMC Meter DefinitionA PMMC meter (also known as a D’Arsonval meter or galvanometer) is defined as a device that measures the current through a coil by observing the coil’s angular deflection in a uniform magnetic field.PMMC ConstructionA PMMC meter (or D’Arsonval meters) is constructed of 5 main components: Stationary Part or Magnet System Moving Coil Control System Damping System MeterWorking PrincipleA PMMC meter uses Faraday’s Laws of electromagnetic induction, where a current-carrying condu

Errors in Measurement DefinitionErrors in measurement are defined as the differences between measured values and true values.Static Error FormulaStatic error is calculated using the formula dA = Am – At, where dA is the error, Am is the measured value, and At is the true value.Limiting ErrorsThe concept of guarantee errors can be cleared if we study this kind of error by considering one example. Suppose there is a manufacturer who manufactures an ammeter, now he should promise or declare that th

What are Electrical Measuring Instruments?Electrical Measuring Instruments DefinitionAn electrical measuring instrument is a tool used to measure electrical parameters.Absolute Measuring InstrumentsAbsolute measuring instruments provide output based on the physical constants of the instruments. Examples include Rayleigh’s current balance and the Tangent galvanometer.Secondary Measuring InstrumentsSecondary measuring instruments are made using absolute instruments and are calibrated by comparing

What is the Measurement of Resistance?Resistance DefinitionResistance is the opposition to electric current flow, a fundamental concept in electrical engineering.Measurement of Low Resistance (<1Ω)Kelvin’s Double BridgeKelvin’s double bridge is a modification of simple Wheatstone bridge. Figure below shows the circuit diagram of Kelvin’s double bridge.As we can see in the above figure there are two sets of arms, one with resistances P and Q and other with resistances p and q. R is the unknown