JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Pre-requisite

Basic Electrical and Electronics Engineering, Network theory &

Electromagnetic fields.

Course objectives:

• To introduce the basic principles of all measuring instruments
• To deal with the measurement of voltage, current, Power factor, power, energy and magnetic measurements.

Course Outcomes

After completion of this course, the student

• Understand different types of measuring instruments, their construction, operation and characteristics
• Identify the instruments suitable for typical measurements
• Apply the knowledge about transducers and instrument transformers to use them effectively.

UNIT - I

Introduction to Measuring Instruments: 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.

UNIT - II

Potentiometers & Instrument transformers: Principle and operation of D.C. Crompton’s potentiometer – standardization – Measurement of unknown resistance, current, voltage. A.C. Potentiometers: polar and coordinate type’s standardization – applications. CT and PT – Ratio and phase angle errors

UNIT - III

Measurement of Power & Energy: 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. 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 – tri-vector meter, maximum demand meters.

R16 B.TECH EEE.

UNIT - IV

DC & AC bridges: Method of measuring low, medium and high resistance – sensitivity of Wheat-stone’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- Maxwell’s bridge, Hay’s bridge, Anderson’s bridge - Owen’s bridge. Measurement of capacitance and loss angle –Desaunty’s Bridge - Wien’s bridge – Schering Bridge.

UNIT - V

Transducers: Definition of transducers, Classification of transducers, Advantages of Electrical transducers, Characteristics and choice of transducers; Principle operation of LVDT and capacitor transducers; LVDT Applications, Strain gauge and its principle of operation, gauge factor, Thermistors, Thermocouples, Piezo electric transducers, photovoltaic, photo conductive cells, and photo diodes. Measurement of Non-Electrical Quantities: Measurement of strain, Gauge sensitivity, Displacement, Velocity, Angular Velocity, Acceleration, Force, Torque, Temperature, Pressure, Vacuum, Flow and Liquid level.

TEXT BOOKS:

• 1. “G. K. Banerjee”, “Electrical and Electronic Measurements”, PHI Learning Pvt. Ltd., 2nd Edition, 2016
• 2. “S. C. Bhargava”, “Electrical Measuring Instruments and Measurements”, BS Publications, 2012.

REFERENCE BOOKS:

• 1. “A. K. Sawhney”, “Electrical & Electronic Measurement & Instruments”, Dhanpat Rai & Co. Publications, 2005.
• 2. “R. K. Rajput”, “Electrical & Electronic Measurement & Instrumentation”, S. Chand and Company Ltd., 2007.
• 3. “Buckingham and Price”, “Electrical Measurements”, Prentice – Hall, 1988.
• 4. “Reissland, M. U”, “Electrical Measurements: Fundamentals, Concepts, Applications”, New Age International (P) Limited Publishers, 1st Edition 2010.
• 5. “E.W. Golding and F. C. Widdis”, “Electrical Measurements and measuring Instruments”, fifth Edition, Wheeler Publishing, 2011. R16 B.TECH EEE.