IITKGP: Measurements and Electronic Instruments Measurements and Electronic Instruments
Spring 2019

Conducted by Avishek Chatterjee



SUBJECT NO-EE21004
SUBJECT NAME- MEASUREMENTS AND ELECTRONIC INSTRUMENTS
LTP- 3-1-0,CRD- 4

SYLLABUS:
[Electrical Measurements:] Sensitivity of d.c bridge, measurement of low and high resistances, d.c. potentiometer, principles of a.c. bridges for measurement of L and C; Instrument specifications and error analysis; Extension of Instrument range: CT and PT.D Arsonval Galvanometer, moving coil meters, dynamometer type wattmeter and induction type energymeter, Hall effect sensor
[Electronic Instruments:] Electronic voltmeter, precision rectifiers, true r.m.s voltmeter; basics of digital measurements: A/D and D/A converters, programmable gain amplifier- auto-ranging; comparators and function generators; elements of digital multimeter; clamp-on meter; solid state energymeter, frequency, phase angle and time period measurement. Cathode Ray Oscilloscope, Digital Storage Oscilloscope.Sample and Hold circuits, Data Acquisition Systems.

Syllabus for GATE examination (Section 8)
[Electrical Measurements:] Bridges and Potentiometers, Measurement of voltage, current, power, energy and power factor; Instrument transformers, Error analysis
[Electronic Instruments:] Digital voltmeters and multimeters, Phase, Time and Frequency measurement; Oscilloscopes..

Syllabus for IES examination (Section 4)
[Electrical Measurements:] Units and Standards. Error analysis, measurement of current, Voltage, power, Power-factor and energy. Indicating instruments. Measurement of resistance, inductance, Capacitance and frequency. Bridge measurements.
[Electronic Instruments:] Data acquisition systems. A/D and D/A converters.
[Not covered here:] Transducers and their applications to the measurement of nonelectrical quantities like temperature, pressure, flow-rate displacement, acceleration, noise level etc.




Chapters Videos
Comments
1 Electromechanical instruments
Chapter 3 of David Bell's Book
Sections to read:
3-2 (operating forces only),
3-3,
3-4,
3-5 (Only simple attraction and siple repulsion type),
3-6(Excluding Quadrant-type Electrostatic Voltmeter),
3-8		 Demonstrations from Youtube My recordings
2 Electromechanical Ammmeters, Voltmeters and Ohmmeters
Chapter 4 of David Bell's Book
Sections to read:
4-1,
4-2,
4-3,
4-4,
4-5
3 Low, Medium and High Resistance Measurement
Chapter 8 of David Bell's Book
Sections to read:
8-1,
8-2,
8-3 (Only four-terminal Resistors and Kelvin Bridge),
8-5 (only Voltmeter and Ammeter Method and Guard wire and Guard Ring),
8-6 (if time permits only Hand-cranked Megohmmeter)
4 Electro-mechanical wattmeters and energy meters
Chapter 16 of David Bell's Book
Sections to read:
16-1,
16-2,
16-3 (if time permits),
16-4 (excluding single wattmeter method),
16-5, 16-7 (excluding energy meter error sources and correction)
5 Potentiometers: DC and AC
Chapter 14 of David Bell's Book
Sections to read:
14-3 (Basic DC Potentiometer),
14-4 (Kelvin-Varley Voltage Divider),
14-5,
Additional: Question: Why or when Potentiometers are used? Ans: No loading current
6 Impedence Measurement: AC Bridges
Chapter 9-10 of David Bell's Book
Sections to read:
9-1,
Chapter 10 Completely,
DON'T Memorize the names of the bridges. We shall never ask you to draw Maxwell, Anderson, Carey-Foster, ... bridges
DO
  • Understand and remember the generic bridge balance equation both in product form as well as ratio form
  • Be able to quickly recognize whether a given bridge can be balanced or not
  • Most bridges are either a product bridge or a ratio bridge, be able to quickly find the balance equation of such a bridge
  • Be able to find bacance equation of any arbitrary bridge
  • Be able to design a product or a ratio bridge to measure an unknown inductance or capacitance and find the balance equation
  • Be able to design a product or a ratio bridge to measure an unknown inductance or capacitance under the constraints such as you do not have any standard inductor (or capacitor) or you do not have standard high (or low) value resistances etc.
  • Understand that in AC bridges the balance is obtained through iterative and alternate tuning where the convergence is an isuue
7 Instrument transformers: CT & PT
A Note from the Book by Stout
What you should know
  • Why or wnen instrument transformers are used?
  • Equivalent circuit of a transformer
  • Phasor diagram of a transformer
  • Why insturument transformers are used (range changing, safety and other causes)?
  • What is ratio error?
  • What is phase angle error and in what context this is important?
  • To justify from the phasor diagram or equivalent circuit why the leakage impedance should be minimized in a PT?
  • Why the no-load current should be small in a CT?
  • Why the secondary of a PT should never be shorted?
  • why the secondary of a CT should never be opened?
8 Measurement errors
Chapter 2 of David Bell's Book
Sections to read:
2-3,
9 Miscellaneous
Magnetic Measurement: Chapter 17 of David Bell's Book
Sections to read: 17-2 (Hall effect Sensor), 17-3 (Magnetic Fulx measuremet with a Ballistic Galvanometer)

Chapter-wise Review Questions


Chapter-wise Tutorial Problems


Chapters Materials
 Comments
1 From Flip-Flops to Couters
Chapter 6 of David Bell's Book
Sections to read:
6-1,
6-3,
6-4
 Board work
2 Op-Amp
 Board work
3 Digital Frequency meter
Chapter 7 of David Bell's Book
Sections to read:
7-3,
7-4,
7-5,
 Board work, Board work
4 Digital Voltmeter
Chapter 7 of David Bell's Book
Sections to read:
7-1,
 Board work
5 ADC and DAC
Chapter 6 of David Bell's Book
Sections to read:
6-5,
6-6,
6 Instrumentation with opamps
Chapter 5 of David Bell's Book
Sections to read:
5-2,
5-3,
5-4,
5-5,
 Board work
7 Instrumentation with transistors
Chapter 5 of David Bell's Book
Sections to read:
5-1,
 Board work
8 Function Generators
Chapter 13 of David Bell's Book
Sections to read:
13-2,
13-3,
 Board work








Laboratory Manual Video-Assistance (Background Theory)
1 e
2 Calibration of a Wattmeter with a DC Potentiometer
3 e
4 Experimental determination of the Parameters of Dynamics of a Galvanometer
5 e
6 Virtual Instrumentation using Labview
7 Electronic Voltmeter circuits
8 e
9 Linear Capacitance meter with IC 555 timer
10 e
11 e
12 Instrumentation Amplifier





Link to the Google group
To send joining request, kindly use the joining password which is sent to you through ERP. Those who have not registered in the ERP yet, but are authentic students can get the password from your friends who have already registered. Outsiders are not allowed in this group so that we can give maximum effort for our own students only.