JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisites

Electrical Circuit Analysis-1 & Electrical Circuit Analysis-2, Analog Electronics

Electro Magnetic 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 magneticmeasurements.
• To understand the basic concepts of smart and digital metering.

Course Outcomes

After learning the contents of this paper the student must be able to

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

Course Objectives Program Outcomes

PO1 PO2 PO3 PO4 PO5 PO6 PO7 PO8 PO9 PO10 PO11 PO12 To introduce the basic 3 3 3 3 3 3 1 1 2 2 1 3 principles of all measuring instruments To deal with the 2 1 2 2 2 2 2 1 1 1 2 3 measurement of voltage, current, Power factor, power, energy and magnetic measurements. To understand the 2 1 2 2 2 2 2 1 1 1 2 3 basic concepts of smart and digital metering

Course Outcomes Program Outcomes

PO1 PO2 PO3 PO4 PO5 PO6 PO7 PO8 PO9 PO10 PO11 PO12 Understand different 2 1 2 2 2 2 2 1 2 1 2 3 types of measuring instruments, their construction, operation and characteristics and identify the instruments suitable for typical measurements Apply the knowledge 2 1 2 2 2 2 2 1 2 1 2 3 about transducers and instrument transformers to use them effectively Apply the knowledge 2 1 2 2 2 2 2 1 2 1 2 3 of smart and digital metering for industrial applications

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.

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. INTRODUCTION TO SMART AND DIGITAL METERING: Digital Multi-meter, True RMS meters, Clamp- on meters, Digital Energy Meter, Cathode Ray Oscilloscope, Digital Storage Oscilloscope.

TEXTBOOKS:

• 1. A. K. Sawhney, “Electrical & Electronic Measurement & Instruments”, Dhanpat Rai & Co. Publications, 2005.
• 2. Dr. Rajendra Prasad, “Electrical Measurements & Measuring Instruments”, Khanna Publishers 1989.

REFERENCE BOOKS:

• 1. G. K. Banerjee, “Electrical and Electronic Measurements”, PHI Learning Pvt. Ltd., 2nd Edition, 2016.
• 2. R. K. Rajput, “Electrical & Electronic Measurement & Instrumentation”, S. Chand and Company Ltd., 2007.
• 3. S. C. Bhargava, “Electrical Measuring Instruments and Measurements”, BS Publications, 2012.
• 4. Buckingham and Price, “Electrical Measurements”, Prentice – Hall, 1988.
• 5. Reissland, M. U, “Electrical Measurements: Fundamentals, Concepts, Applications”, New Age International (P) Limited Publishers, 1st Edition 2010.
• 6. E.W. Golding and F. C. Widdis, “Electrical Measurements and measuring Instruments”, fifth Edition,Wheeler Publishing, 2011.