Electrical Measurements Notes – EM Notes
Electrical Measurements Notes Objective :
Electrical measurements course introduces the basic principles of all measuring instruments. It also deals with the measurement of RLC parameters voltage, current Power factor, power, energy and magnetic measurements.
Electrical Measuremente Notes :-
Classification – deflecting, control and damping torques – Ammeters and Voltmeters – PMMC, moving iron type instruments – expression for the deflecting torque and control torque – Errors and compensations, extension of range using shunts and series resistance. Electrostatic Voltmeters-electrometer type and attracted disc type – Extension of range of E.S. Voltmeters.
CT and PT – Ratio and phase angle errors – design considerations Type of P.F. Meters – dynamometer and moving iron type – 1-ph and 3-ph meters – Frequency meters – resonance type and Weston type – synchroscopes.
Measurement of Power
Single phase dynamometer wattmeter, LPF and UPF, Double element and three element dynamometer wattmeter, expression for deflecting and control torques – Extension of range of wattmeter using instrument transformers – Measurement of active and reactive powers in balanced and unbalanced systems.
Measurement of Energy
Single phase induction type energy meter – driving and braking torques – errors and compensations – testing by phantom loading using R.S.S. meter. Three phase energy meter – trivector meter, maximum demand meters.
UNIT – V
Principle and operation of D.C. Crompton’s potentiometer – standardization – Measurement of unknown resistance, current, voltage.
A.C. Potentiometers: polar and coordinate types standardization – applications.
UNIT – VI
Method of measuring low, medium and high resistance – sensitivity of Wheatstone’s bridge – Carey Foster’s bridge, Kelvin’s double bridge for measuring low resistance, measurement of high resistance – loss of charge method.
Measurement of inductance, Quality Factor – Maxwell’s bridge, Hay’s bridge, Anderson’s bridge, Owen’s bridge. Measurement of capacitance and loss angle – Desauty bridge. Wien’s bridge – Schering Bridge.
UNIT – VIII
Ballistic galvanometer – equation of motion – flux meter – constructional details, comparison with ballistic galvanometer.
TEXT BOOK: Electrical Measurements Notes – EM Notes – EM Pdf Notes
- Electrical Measurements and measuring Instruments – by E.W. Golding and F.C. Widdis, fifth Edition, Wheeler Publishing.
- Electrical & Electronic Measurement & Instruments by A.K.Sawhney Dhanpat Rai & Co. Publications.
REFERENCE BOOKS: Electrical Measurements Notes – EM Notes – EM Pdf Notes
- Electrical Measurements – by Buckingham and Price, Prentice – Hall
- Electrical Measurements by Harris.
- Electrical Measurements: Fundamentals, Concepts, Applications – by Reissland, M.U, New Age International (P) Limited, Publishers.