# Electrical and Electronic Measurements -2 Syllabus Diploma in Electrical Engineering, Regulation 2010, Short Suggestion, Exam Dates, Exam Routine, Question Out, Book list with code

To provide the student with an opportunity to acquire knowledge, skills and attitude in the area of Electrical Measurement and Measuring Instruments with special emphasis on :

• extension of instrument range
• operation of instrument transformer.
• measurement of the resistance of various ranges.
• Concept of operation of synchroscope, CRO and High voltage measurement.
• the concept of operation of meters for measurement of frequency, power factor, temperature, pressure, speed and flow.

## SHORT DESCRIPTION

Extension of instrument ranges: instrument range; Ammeter shunt, Voltmeter multiplier; Instrument transformer: construction and use of CT & PT; Measurement of resistance: Low resistance, Medium resistance and High resistance; Multimeter; Digital instrument; Frequency Meter: Principle of measurement, construction and operation; Power factor meter: Construction and principles of operation; Digital power factor meter; Synchroscope; Cathode Ray Oscilloscope: construction, operation and application; Electronic voltmeter; Special meters: meters for temperature, pressure, speed and flow measurements.

Theory:

# EXTENSION OF INSTRUMENT RANGE

• Understand extension of instrument range.
• List different types of instrument for which extension is required.
• Explain the necessity for extension of instrument range.
• Describe the principles of extension of instrument range.
• Understand the concept of ammeter shunt.
• Describe the ammeter shunt for DC circuit.
• Express the deduction of the relation:
• Explain ammeter shunt for AC circuit.
• Solve problems relating to ammeter shunt.
• Understand the concept of voltmeter multiplier.
• Describe voltmeter multiplier.
• Describe the swamping resistance.
• Explain voltmeter multiplier for AC instrument.
• Solve problems relating to voltmeter multiplier.

# INSTRUMENT TRANSFORMER

• Understand the concept of instrument transformer.
• Describe current transformer (CT) and potential transformer (PT).
• List the applications of current transformer and potential transformer.
• Explain the advantages and disadvantages of CT and PT.
• Describe the burden of instrument transformer.
• Compare instrument transformer with power transformer.
• Understand the concept of current transformer (CT).
• Describe the construction of current transformer.
• Draw the connection diagram of CT with line.
• Draw and explain the vector diagram of current transformer.
• Determine actual current ratio, ratio error and phase angle error.
• Explain the characteristics of current transformer.
• Explain the classes of accuracy in instrument transformer.
• Explain the effect of open circuited secondary of current transformer.
• Describe the construction and use of clip on ammeters.
• Understand the operation of potential transformer (PT).
• Describe the construction of potential transformer.
• Draw the connection diagram of PT with line.
• Draw the vector diagram of PT.
• Draw the circuit showing CT, PT and Watt meter with 1-phase and 3-phase load.

# MEASUREMENT OF RESISTANCE

• Understand the measurement of resistance.
• Classify resistance.
• Explain low, medium and high range of resistance.
• Understand the principle of measurement of low resistance.
• List the methods of measurement of low resistance.
• Describe the measurement of low resistance by ammeter- voltmeter method.
• Describe the measurement of low resistance by Kelvin’s double bridge method.
• Solve problems on Kelvin’s double bridge method.

• Understand the measurement of medium resistance.
• List the method of measurement of medium resistance.
• Describe Wheatstone bridge method of measurement of medium resistance.
• Mention the advantages of Wheatstone bridge method.
• Discuss the precaution in measuring medium resistance by Wheatstone bridge method.
• Solve problems related to Wheatstone bridge method.
• Understand the measurement of high resistance.
• Describe dielectric test of insulating materials.
• List the methods of high resistance measurement.
• Describe the guard wire method of measurement of high resistance.
• Describe the construction and working principle of megger.
• Describe the method of measurement of high resistance by a megger.
• Discuss the uses of megger.
• Describe measurement of earth resistance by earth tester.
• Understand the multimeter.
• Explain the circuit of analog multimeter.
• Describe the construction of analog multimeter.
• Describe the construction of digital multimeter.
• Describe the uses of multimeter.

# FREQUENCY METER

• Understand the principle of measurement of frequency.
• Name the methods of measuring frequency.
• Explain the principle of mechanical resonance and electrical resonance.
• Explain variation of impedance of an inductive circuit with the variation of supply frequency.
• Understand the construction and working principle of frequency meter.
• List different types of frequency meter.
• Describe the construction and working principle of electrical resonance frequency meter.
• Describe the construction and working principle of Weston frequency meter.

• Understand the operation of digital frequency meter.
• Describe the principle of operation of digital frequency meter.
• Sketch the block diagram of a digital frequency meter.
• Describe each block of a digital frequency meter.
• Describe the function of time base selector in digital frequency meter.
• Draw and Explain the operation of logic diagram of a digital frequency meter.

# POWER FACTOR METER

• Understand the construction and principle of operation of power factor meter.
• List different types of power factor meter.
• Describe construction and principle of operation of single phase dynamometer type power factor meter.
• Describe the construction and principle of operation of three phase dynamometer type power factor meter.
• Understand the principle of operation of digital power factor meter.
• Describe the principle of operation of digital power factor meter.
• Draw the block diagram of a digital power factor meter.
• Describe each block of a digital power factor meter.

# SYNCHROSCOPE

• Understand the construction and principle of operation of synchroscope.
• State synchronism and conditions for synchronizing of alternators.
• List the method of synchronization of alternators.
• Describe the construction and working principle of electrodynamometer (Weston) type synchroscope.
• Describe the construction and working principle of moving iron type synchroscope.

# CATHODE RAY OSCILLOSCOPE

• Understand the principle of cathode ray oscilloscope.
• List various types electrodes of a cathode ray tube (CRT).
• Sketch the diagram of a cathode ray tube with various electrodes.
• Describe the construction and working principle of a cathode ray tube.
• Draw the block diagram of a basic cathode ray oscilloscope (CRO).
• Describe the function of different control knob in cathode ray oscilloscope.
• Explain the operation of time base generator in CRO.
• Explain the operation of horizontal and vertical amplifier in CRO.
• Describe the function of trigger circuit.
• Describe different wave forms in CRO for different signal inputs.
• Describe the process of measurement of voltage, current, phase and frequency by CRO.
• List the applications of CRO.
• Describe lissajous pattern.

HIGH VOLTAGE MEASUREMENT

• Understand the principle of high voltage measurement and testing.
• Describe the high voltage measurement of electrical quantities.
• List the equipment for high voltage measurement.
• Describe the sphere gap method of high voltage measurement.
• Describe the potential divider method of high voltage measurement.
• Mention the advantages of sphere gap method of high voltage measurement.
• Mention the disadvantages of sphere gap method of high voltage measurement.
• Understand the operation of maximum demand indicator.
• Explain the necessity of maximum demand indicator,
• Describe the construction and working principle of Wright maximum demand indicator and Merz price maximum demand indicator.
• Sketch the connection diagram of maximum demand indicator.

# SPECIAL METERS

• Understand the measurement of temperature.
• List the names of temperature measuring meter.
• Describe the principle of operation of electrical resistance thermometer.
• Discuss the requirement of a conductor material to be used in resistance thermometer.
• Describe shortly platinum resistance thermometer.
• Understand the principle of measurement of pressure.
• List different types of pressure measuring meter.
• Describe measurement of pressure by using electrical transducers as secondary transducers.
• Discuss the force summing device.
• Discuss the secondary transducers.
• Describe the measurement of pressure with diaphragm element and inductive transducer.

• Understand the principle of measurement of speed.
• List the names of tachometers.
• Describe a DC tachometer.
• Discuss the disadvantages of a AC tachometer.
• Describe an AC tachometer.
• Understand the principle of measurement of flow.
• Name different flow measuring meter.
• Describe the construction of turbine flow meter.
• Describe the working principle of turbine flow meter.

# Practical:

• Determine the shunt resistance of an ammeter for extension of its range.
• Sketch the circuit diagram for determining the shunt resistance of an ammeter.
• Collect the tools, equipment and materials required.
• Prepare the circuit according to the circuit diagram using proper equipment.
• Check the equipment setting and connection before connecting power supply.
• Record the readings from the meter.
• Calculate the value of shunt resistance.
• Determine the value of resistance of a voltmeter multiplier.
• Sketch the circuit diagram for determining the resistance of voltmeter multiplier.
• Connect the tools, equipment and materials required.
• Prepare the circuit according to the circuit diagram.
• Check the circuit before connecting power supply.
• Record the reading from the meter.
• Calculate the value of resistance of the multiplier.
• Perform the handling of instrument transformer.
• Select the current transformer and potential transformer.
• Select required tools, equipment and materials.
• Draw the circuit diagram.
• Connect the equipment according to the circuit diagram.
• Check all connection before supplying energy to the circuit.
• Records reading from the meter and calculate the transformation ratio.
• Perform the measurement of low resistance by Ammeter–Voltmeter method.
• Draw the circuit diagram for the measurement of low resistance by ammeter-voltmeter method.
• Connect the tools, equipment and materials required.
• Prepare the circuit according to the circuit diagram using proper equipment.
• Check the circuit before connecting power supply.
• Record the meter readings.
• Calculate the resistance from the meter readings.
• Perform the measurement of earth resistance by earth tester.
• Sketch the circuit diagram for the measurement of earth resistance by earth tester.
• Select a earth tester and required tools, equipment and materials.
• Connect the equipment according to the circuit diagram.
• Measure the earth resistance from the reading of the earth tester.
• Perform the measurement of medium resistance by wheatstone bridge.
• Draw the circuit diagram for measuring medium resistance by Wheatstone bridge.
• Select tools, equipment and materials required.
• Prepare the circuit according to the circuit diagram.
• Check all the connection before connecting power supply.
• Record the meter readings.
• Calculate the value of unknown resistance.
• Perform the measurement of high resistance by a megger.
• Select a high resistance.
• Select a megger.
• Connect the resistance with the megger.
• Measure the resistance from the reading of the megger.
• Perform the measurement of frequency by a frequency meter.
• Sketch the circuit diagram.
• Select a frequency meter.
• Select tools, equipment and materials.
• Connect the frequency meter to the supply or circuit whose frequency is to be measured.
• Measure the supply frequency from the meter.
• Perform the measurement of power factor by a power factor meter.
• Sketch the circuit diagram for measurement of power factor of a load by a power factor meter.
• Select the tools, equipment and materials required.
• Prepare the circuit according to the circuit diagram by using proper equipment.
• Check the circuit before connecting power supply.
• Record power factor from the power factor meter.

• Perform the measurement by cathode ray oscilloscope and observe wave shape.
• Choose a cathode ray oscilloscope (CRO).
• Select a signal generator.
• Select tools and materials required.
• Connect the signal generator and CRO properly.
• Identify the control and function knobs of signal generator and CRO.
• Energize the signal generator and CRO.
• Observe the operation of different control knobs of CRO.
• Observe wave form on the screen.
• Perform the measurement of voltage, current and frequency by cathode ray oscilloscope (CRO).
• Draw the circuit diagram for the measurement of voltage, current and frequency by CRO.
• Select the tools, equipment and materials required.
• Connect the equipment setting and connection according to the circuit diagram.
• Measure the voltage, current and frequency of the circuit by CRO.
• Prepare a report on it.

### 12           Measure high voltage peak value.

• Select sphere gap test equipment.
• Connect the sphere gap equipment terminals with high voltage source.
• Adjust the gap up to flash over occurred.
• Take sphere size, gap, length, embient temperature & pressure.

Find the value of voltage by using calibration table and taken data