Contents

• 1. Measuring Instrument

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  Classification of Instruments, Absolute Instruments, Secondary Instruments, Classification of Ammeter and Voltmeters, Permanent Magnet Moving Coil (PMMC), Principle of Operation, Construction of PMMC, Working of PMMC, Torque Equation, Scale Shape, Errors in PMMC Instruments, Advantages and Disadvantages, Uses of PMMC Instrument, Electrodynamometer (Electrodynamic) Instruments, Principal of Operation, Construction of Electrodynamometer Type Instrument, Torque Equation, Scale Shapes, Calibration, Errors in Electrodynamometer Type of Instrument, Advantages and Disadvantages of Electrodynamic Instrument: Advantages, Uses of Electrodynamometer Type Instruments, Moving Iron Instruments, Attraction and Repalsion Type Moving Iron Instrument, Torque Equation of Moving Iron Instrument, Scale Shape, Errors in Moving Iron Instrument, Advantages and Disadvantages, Electrostatic Instruments, Constructional Details, Principle of Operation, Type of Connection, Theory of Electrometer, Torque Equation, Scale Shapes, Advantages and Disadvantages of Electrostatic Instruments, Induction Instruments, Principle of Operations, Errors in Induction Instruments, Applications of Instruments for Measurement of Current and Voltage, Power in DC Circuit, Power in AC Circuit, Electrodynamometer Wattmeters, Construction, Theory of Electrodynamometer Wattmeter, Shape of Scale of Electrodynamometer Wattmeter, Measurement of Power in Single Phase AC Circuits, Wattmeter Errors, Their Compensation And Adjustments, Measurement of Energy, Single Phase Induction Type Energy Meter, Errors and Their Compensation in Induction-type Energy Meters, Energy Meter Adjustments, Testing of Energy Meters, Phantom Loading, Numerical Problems, Review Question.
   
  2. Polyphase Metering

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  Introduction, Blodel’s Theorem for N-Phase P-Wire System, Measurement of Power in Three Phase Balanced and Unbalanced Systems, Three Wattmeter Method, Two Wattmeter Method, One Wattmeter Method, Measurement of Reactive Volt Amperes, Single Phase VARmeter, Polyphase Varmeter, Reactive Power Measurement in Three Phase Circuit, Three Phase Induction Type Energy Meter, Instrument Transformers, Classification, Ratios of Instrument Transformers, Burden of an Instrument Transformer, Advantages of Instrument Transformers, Applications of Instrument Transformers, Current Transformer, Construction of Current Transformer, Operation of Current Transformer, Ratio and Phase Angle Error in Current Transformer, Minimization of Ratio and Phase Angle Errors, Effect of Variation of Power Factor, Secondary Burden and Frequency Change on Errors (Characteristics of CT), Testing of CTs, Potential Transformer, Construction of Potential Transformer (PT), Operation of PT, Ratio and Phase Angle Error in Potential Transformer, Minimization of Ratio and Phase Angle Errors in PT, Effect of Variation of Power Factor, Secondary Burden and Frequency Change on Errors (Characteristics of PT), Testing of PTs, Applications of Instrument Transformer for Measurement of Power, Application of Instrument Transformer in Measurement of Current and Voltage, Applications of Instrument Yransformers, Review Questions.
   
  3. Measurement of Resistance

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  Introduction, Classification of Resistance, Low Resistances, Medium Resistances, High Resistance, Measurement of Low Resistances, Ammeter-Voltmeter Method, Potentiometer Method, Kelvin Double Bridge Method, Ohm-meter Method, Measurement of Medium Resistances, Ammeter-Voltmeter Method, Substitution Method, Wheatstone Bridge Method, Carey Faster Slide Wire Bridge Method, Ohm-meter Method, Measurement of High Resistances, Direct Deflection Method, Loss of Charge Method, Megger Method, Difficulties in the Measurement of High Resistances, Leakage Effects, Absorption Effects, Stray Changes, Effect of Time Electrification, Effect of Temperature Upon Insulation Resistance, Damaging of Instrument, Application of Guard Circuit for Measurement of High Resistance, Measurement of Earth Resistance, Factors, Methods of Measuring Earth Resistances, Numerical Problems, Review Questions, Unsolved Problems.
   
  4. A. C. Bridges

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  Introduction, Generalized Treatment of Four Arm AC Bridges, General Equation for Bridge Balance, Balance Adjustment of AC Bridge, Sources Used in AC Bridges, Interrupters, Microphones Hummers, Alternators, Oscillators, Detectors Used in AC Bridges, Head Phones, Vibrational Galvanometers, Tuneable Amplifier Detectors, Oscilloscope, Characteristics of Detectors, Sensitivity, Easy to Use, Frequency Selectivity, Phase Selectivity, Logarithmic Response, Response Time, Measurement of Self Inductance, Maxwell’s Inductance Bridgez, Maxwell’s Inductance Capacitance Bridge (Maxwell-Wein Bridge), The Hay’s Bridge, Anderson’s Bridge, Measurement of Capacitance, De Sauty’s Bridge, The Schering Bridge, Measurement of Mutual Inductance, Heaviside Bridge, Campbell’s Modification of Heaviside Bridge, Heaviside Campbell Equal Ratio Bridge, Carey-Foster Bridge (Heydweiller Bridge), Measurement of Frequency, Wien’s Bridge, Sources of Errors in Bridge Circuit and Their Elimination, Errors Due to Stray Field Effects, Leakage Errors, Eddy Current Errors, Frequency and Waveform Errors, Residual Errors, Screening of Bridge Components, Wagner’s Earthing Device, Numerical Problems, Review Questions, Unsolved Problems.
   
  5. Potentiometer

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  Introduction, Principle of Operation of the Potentiometer, Types of Potentiometers, DC Potentiometers, AC Potentiometer, Standardization of AC Potentiometer, Factors of Consideration in AC Potentiometers, Applications of Potentiometers, Applications of dc Potentiometer, Application of ac Potentiometer, Numerical Problems, Review Questions, Unsolved Problems.
   
  P. Papers