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Electrical and Electronics Instrumentation Materials & Notes
UNIT 1
INTRODUCTION:JNTU
“AN GREAT SCIENTIST SAID THAT AN ED CATION WHICH CANNOT BE EXPRESSED IN
NUMERICALS IS OF NO USE”.THAT IS EVERY PARAMETERS WE COME ACROOS IN TECHNICAL WORLD
CAN MEASURED IN ONE OR THE OTHER WAY .
THE POWER SYS EM IS ASSOCIA ED BY MANY PARAMETERS WHICH ARE SUPPOSED
TO BE MEASURED AT ONE OR O HER POINT. HENCE MEASUREMENT GOT GREATER IMPORTANCE IN
POWER SYETMS
THIS U IT DEALS WITH CLASSIFICATION OF INSTRUMENT,CLASSIFICATION OF
INSTRUMENT BASED ON THEIR I DICATION AND WORKING CONDITION ,DEFINATION OF THE
MEAUSRING INSTRUME ALO G WITH EXAMPLE,EFFECTS BASED ON WHICH THESE INSTRUMENTS
OPERATE.
COMMON TORQUES IN ELECTRICAL INSTRUMENTS:
FOR THE SMOOTH FUNCTIONING OF MEASURING INSTRUMENT THEY ARE ASSOCIATED
WITH DIFFERENT TYPES OF TORQUES.THEY ARE DEFLECTION, DAMPING AND CONTROL TORQUE. THE
IMPOR TNCE OF EACH TORQUE ANF DIFFERENT ARRANGEMENTS TO PROVIDE ABOVE SAID TORQUES
RE DISCUSSED HERE.
IN MOST OF THE INSTRUMENTS THESE TORQUES ARE PROPORTIONAL TO CURRENT
FLOWING THE CIRCUIT I.E CURRENT IS THE MOST IMPORTANT PARAMETER IN MEASURING DEVICES.
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DISCRIPTION:
THE MAIN CLASIFICATIONS OF VOLTMETER AND AMMETER IN POWER SYSTEM ARE
DEPENDING ON SUPPLY PROVIDED I.E HENECE THE CLASSIFICATION IS MC AND MI INSTRUMENTS,
WHERE MC USED TO MEASURE DC QUANTITIES AND MI TO MEASURE AC QUANTITIES.
THEREFORE IN THE PRECEEDING TOPICS WE SHALL DISCUSS ABOUT THE CONSTRUCTION AND
OPERATION OF MC INSTRUMENTS, THEIR ADVANTAGES AND DISADVANTAGES , DIFFERENT TYPES OF
ERRORS WHICH EFFECTS THE MEASUREMENT USING MC INSTRUMENTS, DIFFERENT METHODS TO
EXTEND THE RANGE OF MC METERS AND SUGGESTING THE BEST METHOD FOR MEASUREMENT.
LATER WE SHALL DISCUSS ABOUT THE CONSTRUCTION AND OPERATION OF MI INSTRUMENTS,
THEIR ADVANTAGES AND DISADVANTAGES , DIFFERENT TYPES OF ERRORS WHICH EFFECTS THE
MEASUREMENT USING MI INSTRUMENTS, DIFFERENT METHODS TO EXTEND THE RANGE OF MI METERS
AND SUGGESTING THE BEST METHOD FOR MEASUREMENT.
THE EXPRESSIONS FOR THE DEFLECTION TORQUE OF MC AND MI INSTRUMENTS ARE DERIVED,
THEIR THE NATURE OF SCALE CAN BE DECIDED.
MEASUREMENTJNTUUSINGELECTRO-STATICVOLTMETERINSTRUMENTS, DIFFERENT METHODS TO EXTEND
IMPORTANT NOTE:
ONE CANT USE THE VOLTMETER AS THEIR LIKE TO MEAS REMENT, IT IS NECESSARY TO IDENTIFY
WHETHER THE GIVEN CIRCUIT IS LOW RESISTIVE OR HIGH RESISTIVE . THIS METHOD OF CHOOSING
VOLTMETER DEPENDS ON I S SENSI IVI Y WHICH IS CALLED AS LOADING EFFECT.
ELECTRO-STATIC VOLTMETERS:
THE INSTRUME WHICH WORKS ON THE PRINCIPLE OF ELECTRO-STATIC IS VOLTMETER. LET US
SEE THE CLSSIFICATION OF ELECTRO-STATIC VOLTMETERS, THEIR CONSTRUCTION AND OPERATION
, THEIR ADVANTAGES A D DISADVA TAGES , DIFFERENT TYPES OF ERRORS WHICH EFFECTS THE
THE RANGE OF THESE METERS AND SUGGESTING THE BEST METHOD FOR MEASUREMENT.
CONCLUSION:
BY THE END OF THIS UNIT ONE CAN BE ABLE IDENTIFY THE TYPE IF ELECTRICAL INSTRUEMNT,
THE IMPORTANCE OF MC, MI AND ELECTROSTATIC INSTRUMENTS IN POWER SYSTEMS
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UNIT 2
INTRODUCTION:
TILL NOW WE KNOW THAT TRANSFORMER IS A DEVICE USED FOR TRANSFORMATION
OF ENERGY, BUT IN PRACTICE TRANSFORMER IS ALSO USED AS PROTECTIVE DEVICE AND ALSO AS
MEASURING DEVICE.
HERE IN THIS UNIT WE SHALL STUDY AN TRANSFORMER IN POWER SYSTEM AS A
MEASURING DEVICE CALLED AS INSTRUMENT TRANSFORMER.
DEFINATION OF INSTRUMENT TRANSFORMER, ITS SIGNIFICANCE IN POWER SYSTEM
AND RATIOS ASSOCIATED WITH IT . THE APPLICATIONS OF INSTRUMENT TRANSFORMER ARE
DISCUSSED.
DISCRIPTION:
LATER THE MAIN CLASSIFICATION OF INSTRUMENT TRANSFORMER IS DONE,
THE
CONSTRUCTION AND OPERATION OF POTENTIAL AND CURRENT TRANSFORMERS ARE DISCUSSED. THE
POTENTIAL TRANSFORMER IS USED TO MEASURE VOLTAGE IN HIGH VOLTAGE CIRCUITS AND THE
CURRENT TRANSFORMER IS USED TO MEAS RE C RRENT IN HIGH CURRENT CIRCUITS. THE
MEASUREMENT OF VOLTAGE AND C RRENT
SING INTR MENT TRANSFORMERS ARE EFFECTED BY
RATIO AND PHASE ANGLE ERROR. THE EXPRESSIONS FOR FOR RATIO AND PHASE ANGLE ERRORS ARE
DERIVED FROM WHICH CHARAC ERIS ICS OF INS R EMNT TRANSFORMER ARE STUDIED.
THE KNOWLEDGE OF PHASOR DIAGRAM OF INSTRUMENT IS VERY IMPORTANT TO
CHARACTERISE THEM . THE LIM A ION OF INS RUMENT TRANSFORMERS IS IMPORATANT BEFORE
TAKING THEM I TO SERVICE. COMPARE THE POTENTIAL AND CURRENT TRANSFORMER FOR BETTER
UNDERSTAND
IN GENERAL TO DETERMINE THE POWER FACTOR OF CIRCUIT THE METHDO WE KNOW IS
VOLTMETER – AMMETER METHOD, BUT THIS METHOD OF MEASUREMENT MAY NOT LEAD TO
PRECISION VALUE. THEREFORE AN NEW DEVICE INTRODUCED INTO THE CIRCUIT CALLED AS POWER
FACTOR METER. POWER FACTOR METER WORKS ON THE PRINCIPLE OF MAGENTIC EFFECT AND
MOTORING OPERATION. IN THE CONSTRUCTION OF POWER FACTOR METER IT GOT UNIQUE PROPERTY
TH T CONTROL TORQUE IS NOT PROVIDED. DEPENIDING ON NATURE OF SUPPLY THEY ARE CLASSIFIED
S 1-PH AND 3-PH POWER FACTOR METER.
IN INDIA NATURAL FREQUENCY IS 50 HZ AND MANY OF THE POWER SYSTEM CIRCUITS
ARE MONITORED AT THIS FREQUENCY, HENEC IT IS NECESSARY
TO CONTINUOUSLY CHECK THE
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FREQUENCY OF SUPPLY. FREQUENCY IN DEFINATION NUMBER OF CYCLES MABE Y WAVE FORM IN ONE
SECOND, IT IS ALSO GIVEN AS RECIPROCAL OF TIME. THE DEVICE USED TO MEASURE FREQUENCY IS
CALLED AS FREQUENCY METER. DEPENDING ON MEACHANICAL AND ELECTRICAL RESONANCE
THE
FREQUENCY METERS ARE CLASSIFIED. LATER THE CONSTRUCTION AND OPERATION OF FREQUENCY
METERS ARE STUDIED.
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THE SYNCHROSCOPE IS A DEVICE WHICH IS USED TO DETERMINE THE CORRECT INSTANT TO
CLOSE THE SWITCH SUCH THAT INCOMING GENERATOR AND BUS BAR ARE SYNCHRONISED. THIS
PPROCESS OF CLOSING SWITCH IS CALLED AS SYNCHRONIZATION. THE CONDITIONS FOR
SYNCHRONIZATION OF ALTERNATOR AND BUS BAR ARE---
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VOLTAGES MUST BE SAME.
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FREQUENCY MUST BE SAME.
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PHASE SEQUENCE MUST BE SAME.
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PHASE MUST BE SAME.
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IN THE PRECEEDING THE ADVANTAGES AND DISADVANTAGES OF POWER FACTORMETER,
FREQUENCY METER AND SYNCHROSCOPE ARE ST DIED.
CONCLUSION:
IN THE POWER SYS EMS HE INS RUEMENT TRANSFOEMERS, FREQUENCY METER AND
SYNCHROSCOPE GOT THEIR OWN IMPORA NCE, HENCE IT IS NECESSARY FOR EVERY ELECTRICAL
ENGINEER TO HAVE THE K OWLEDGE OF THESE INSTRUMENTS.
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UNIT 3
INTRODUCTION:
THE WORD POWER GOT VERY IMPORTANCE IN ELECTRICAL WORLD. GENERALLY
POWER IN ELECTRICAL CIRCUITS IS GIVEN AS PRODUCT OF VOLTAGE AND CURRENT. BUT DEPENDING
ON THE NATURE OF SUPPLY THE DC POWER IS GIVEN AS V*I AND AC POWER IS V*I*COSINE OF PHASE
BETWEEN V AND I.
IN THE POWER SYSTEM WE COME ACROSS THREE TYPES OF POWER ACTIVE POWER,
REACTIVE POWER AND APPARENT POWER. HERE IN THIS UNIT WE SHALL DISCUSS ABOUT
MEASUREMENT OF ACTIVE AND REACTIVE POWER .
DISCRIPTION:
MEASUREMENT OF POWER IN DC AND AC CIRCUITS. TO MEASURE THE POWER IN DC
CIRCUITS THE BEST METHOD IS VOLT-AMP METHODS. THERE ARE T
O CONNECTIONS OF VOLT-AMP
METHOD FORJNTUMEASUREMENTOFPOWER.BUTTHESETWO CONNECTIONS MAY NOT LEAD TO THE
EXACT POWER MEASUREMENT CONS MED BY LOAD. B T THERE IS NO OTHER ALTERNATIVE METHOD
TO MEASURE POWER IN DC CIRC ITS, HENCE IT IS NECESSARY TO CALCULATE ERROR IN THE
MEASUREMENT USING THIS METHOD.
TO MEASURE HE POWER IN AC CIRC ITS A DEVICE CALLED WATTMETER IS CAME INTO
EXISTENCE. THIS WATTME ER IS MAINLY MEANT TO MEASURE USEFULL POWER ONLY.IN THE
CONSTRUCTION OF WATTME ER IT CONSIS S OF PRESSURE COIL AND CURRENT COIL, WHERE THE
PRESSURE IS EXITED BY VOLTAGE TO BE MEASURED AND CURRENT COIL BY CURRENT TO BE MEASURED.
THE UNIQUENESS OF CURRE T COIL IS IT IS HIGHLY RESISTIVE AND PRESSURE COIL AND CURRENT COIL
IS COMBINELY CALLED AS ELEME . AN DOUBLE ELEMENT WATTMETER IS USED TO MEASURE POWER
IN POLY PHASE CIRCUIT.
MEASUREMENT OF POWER IN POLY PHASE CIRCUIT IS GIVEN BY STATEMENT NAMED
BLONDEL’S THEOREM. THE BLONDEL’S THEOREM IS PROVED FOR--1)
2)
3)
4)
5)
3 PHASE 3 WIRE SYSTEM.
3 PHASE 4 WIRE SYSTEM..
SINGLE WATTMETER METHOD .
TWO WATTMETER METHOD.
THREE WATTMETER METHOD.
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LATER THE CONSTRUCTION OF DOUBLE ELEMENT WATTMETER AND ITS TORQUE
EQUATION ARE DERIVED. THESE WATTMETERS ARE LIMITED FOR 600V AND 20 A IN GENERAL , BUT
PRACTICALLY VERY HIGH VOLATGE AND HIGH CURRENTS MAY EXIST , TO MEASURE POWER IN SUCH
CIRCUITS WE NEED TO INCREASE THE RANGE OF WATTMETER.
THE EXTENSION OF RANGE OF WATTMETER CAN BE DONE USING INSTRUMENT
TRANSFORMERS.THEN LPF AND FERRO-DYNAMIC WATTMETER CONSTRUCTION AND THEIR OPERATION
IS STUDIED.
THE MEASUREMENT OF POWER USING WATTMETER IS EFFECTED BY DIFFERENT
TYPES OF ERRORS, THEY ARE----ERROR DUE TO INDUCATNCE OF PRESSURE COIL WICH LEADS TO
DERIVATION OF CORRECTION FACTOR, ERROR DUE TO CONNECTIONS WHICH IS UNAVOIDABLE ONLY
POSSIBILITY IS CHOOSING THE CORRECT CONNECTIONS DEPENDING ON NATURE OF LOAD, ERROR DUE
TO FREQUENCY OF SUPPLY, ERROR DUE TO MUTUAL INDUCTANCE BETWEEN TWO COILS ETC.
CONCLUSION:
IT IS VERY MUCH NECESSARY TO CONTINUOUSLY MONITOR THE POWER IN DIFFERENT
PARTS OF POWER SYSTEMS , TO KNOW THE POWER LOSSES IN PO
ER SYSTEM AT GENERATION ,
TRANSMISSION AND DISTRIBUTION LEVELS, TO DETERMINE THE EFFFICIENCY OF VARIOUS EQUIPMENTS
IN POWER SYSTEMS MEASUREMENT OF POWER IS MOST IMPORATNT-----HENCE ABOVE SAID CAN BE
MEET BY USING WATTMETER TO MEAS RE THE POWER.
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UNIT 4
INTRODUCTION:
ANY COUNTRY IS CALLED AS DEVELOPED COUNTRY DEPENDING ON THEIR ENERGY
CONSUMPTION, TO MEET THAT DEMAND THE GENERATION HAS TO INCREASE RAPIDLY IN ONE OR THE
OTHER WAY.
WE KNOW THE POWER TRANSMISSION IN INDIA IS OPERATED AT 50 Hz FREQUENCY.
THEREFORE THE ENERGY CONSUMPTION IN INDIA MEASURED IN TERMS OF ENERGY UNITS WHERE
EACH UNIT REPRESENTS ONE KWH.THEREFORE MEASUREMENT OF ENERGY ALSO PLAYS IMPORATNT IN
POWER SYSTEMS AND ALSO FOR THE ECONOMMY OF COUNTRY.
IN THE DEFINATION ENERGY IS CAPACITY TO DO
CONSUMED OVER A SPECIFIED PERIOD OF TIME.
ORK OR AMONT OF POWER
THE ENERGY MEASUREMENT CAN BE DONE IN DC AND AC CIRCUITS
SEPRATELY.COMBINELY THE DEVICE USED TO MEASURE ENERGY IS CALLED AS MOTOR METERS.
THE DEVICE USED O MEAS RE ENERGY IN DC CIRCUITS IS CALLED AS WATTHOUR
METER AND AMPERE HOUR ME ER AND IN AC CIRC ITS ENERGYMETER.
DISCRIPTION:
E ERGY METER IS AN ELECTRO-MAGNETIC DEVICE USED TO MEASURE ENERGY IN AC
CIRCUITS. DEPE DI G ON SUPPLY THEY ARE CLASSIFIED AS 1-PHASE AND 3-PHASE ENERGYMETER. IN
THE CONSTRUCTION OF ENERGYMETER MAINLY IT CONSISTS OF PRESSURE COIL AND CURRENT COIL ,
WHERE PRESSURE COIL IS HIGHLY INDUCTIVE . UNLIKE DEFLECTION TORQUE IN INDICATING
INSTRUMENTS ENERGYMETERS ARE ASSOCIATED WITH DRIVING TORQUE , AS MEASUREMENT OF
ENERGYMETER IN DONE IN TERMS OF DRIVEN AL DISC. SIMILARLY LIKE CONTROL TORUE IN INDICATING
INSTRUMENTS BRAKING TORQUE IS PROVIDED FOR ENERGYMETERS. THE REGISTERING SYSTEM IN
MANY OF INSTRUMENTS IS AN ANGLED SCALE ON WHICH POINTER DEFLECTS WHERE AS IN
ENERGYMETER CYCLOMETER TYPE REGISTERING SYSTEM IS USED.THE TORQUE GOVERNING THE
ENERGYMETER IS PROPORTIONAL TO SPEED OF THE AL DISC OR TOTAL NUMBER OF REVOLUTION MADE
BY L DISC IN SPECIFIED PERIOD OF TIME.THE MEASUREMENT OF ENERGY USING ENERGYMETER IS
EFFECTDE DIFFERENT TYPES OF ERRORS AND WE DEAL COMPENSATIONS FOR ERRORS .
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MEASUREMENT OF ENERGY IN POLY PHASE CIRCUITS IS DONE POLY PHASE ENERGYMETER WHICH IS
ALSO CALLED AS DOUBLE ELEMENT AND THREE ELEMENT ENERGYMETER. THE CONNECTIONS INTO
CIRCUIT ARE SIMILAR TO TWO WATTMETER AND THREE WATTMETER METHOD RESPECTIVELY.
TO TEST WHETHER THE MEASUREMENT GIVEN BY ENERGYMETER CORRECT OR
NOT WE CAN TEST USING RSS METER .THE TESTS CONDUCTED ARE NAMED AS
1. TEST-A (LONG PERIOD DAIL TEST)
2. TEST-B(SHORT PERIOD DAIL TEST)
3. TECT-C(INDICATING INSTRUMENTS TEST)
LATER THE CONSTRUCTION AND OPERATION OF TRIVECTOR METER, MAXIMUM
DEMAND METER IS STUDIED.
CONCLUSION:
THE WORD ENERGY IS THE MOST IMPORTANT PART IN POWER SYSTEM. AFTER THIS UNIT
AN STUDENT CAN BE ABLE OF MEASURING ENERGY IN SINGLE PHASE AND POLY PHASE CIRCUITS ALONG
WITH BASIC KNOWLEGDE OF ITS CONSTR CTION AND OPEARTION.
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UNIT 5
INTRODUCTION:
TILL KNOW THE VOLTMETER WHAT WE HAVE STUDIED IS USEFUL IN MEASURING
VOLTAGE GREATER THAN 50 V AND SO, BOTH IN DC AND AC CIRCUITS.BUT WE ARE SUPPOSED TO
KNOW THE METHOD ARE DEVICE USING WHICH WE CAN MEASURE SMALL VOLATGES LESS THAN 2 V.
THE BEST METHOD TO MEASURE LOWER VOLTAGES IN POWER SYSTEM IS USING POTENTIOMETER
EITHER IN DC OR AC CIRCUITS.
IN THE DEFINATION POTENTIOMETER IS A DEVICE USED TO MEASURE SMALL
VOLTAGES IN POWER SYSTEMS AND POWER NETWORKS.
DISCRIPTION:
HERE WE SHALL DISCUSS THE CONSTRUCTION AND OPERATION OF DC POTENTIOMETER.
MEASUREMENT OF VOLTAGE USING POTENTIMETER IS AN COMPARISON METHOD, HENCE IT GOT AN
ADVANTAGE OF MEASURING VOLTAGE AT LOW POWER CONSUMPTION AS IT WORKS ON NULL
DFLECTION PRINCIPLE.
IN THE CONS RUC ION OF PO EN IOMETER IT MAINLY CONSISTS OF BATTERY, SERIES
RHEOSTAT, SLIDE WIRE, STNADARD CELL AND HE ELEMENT ACROSS WHICH WE ARE SUPPOSED TO
FIND VOLTAGE. IN THE WORKING OF PO NE IOMETER IT UNDERGOES TWO MODES—CALIBRATION
AND OPERATION.
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CALIBRATION IS DO E TO KNOW WHETHER THE POTENTIOMETER GIVES EXACT
READI G ARE OT. IN THE PROCESS THE ADJUSTMENT OF WORKING CURRENT IN SLIDE
WIRE SUCH THAT SLIDE WIRE COLTAGE MATCHES WITH STANDARD CELL VOLTAGE IS
CALLED AS STA DARDIZATION.
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THEN OPERATE POSITION WHERE THE UNKNOWN VOLATGE IS MEASURED USING
CALIBRATDE SLIDE WIRE.
THEN THE MEASUREMENT OF HIGH VOLTAGES USING POTENTIOMETER IS DONE USING
VOLT- RATIO BOX.DC POTENTIOMETER GOT MANY APPLICATIONS LIKE CALIBRATION OF AMMETER,
VOLTMETER, WATTMETER AND MEASUREMENT OF RESISTANCE, POWER ETC.
THE AC POTENTIOMETER IS AN DEVICE WHICH IS USE TO MEASURE AC VOLATGE, UNLIKE IN
DC THESE POTENTIOMETERS ARE USED TO MEASURE BOTH MAGNITUDE AND PHASE OF OF AC
VOLATGE. THESE POTENTIOMETERS ARE CALIBRATED WITH BOTH DC AND AC SUPPLY. DEPENDING ON
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NATURE OF MEASURING VALUE THEY ARE CLASSIFIED AS POLAR TYPE AND CO-ORDINATE TYPE
POTENTIOMETER.
BY THE DEFINATION POLAR TYPE ARE ONE WHERE MEASUREMENT IS DONE AS
MAGNITUDE AND PHASE OF UNKNOWN VOLATEG
AND CO-ORDINATE TYPE ARE ONE WHERE
UNKNOWN VOLTAGE IS MEASURED AS IN PHASE AND QUADRATURE COMPONENT OF UNKNOWN
VOLATGE.
AC POTENTIOMETERS ALSO GOT APPLICATIONS LIKE CALIBRATING VOLTEMETER ,
AMMETER, MEASUREMENT OF POWER , UNKNOWN REACTANCE ETC.
CONCLUSION:
IN THE POWER SYSTEMS THER ARE PARTS, DEVICES OR EQUIPMENT HERE THE
VOLATGE TO BE MEASURED IS SO SMALL, WHICH CANT BE DONE BY LABORATORY SIZE VOLTMETERS,
HENCE THEIR COMES THE IMPORTANCE OF POTENTIOMETERS
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UNIT 6
INTRODUCTION:
THE MOST IMPORTANT PARAMETER AROUND WHICH THE ENTIRE POWER SYSTEMS
REVOLVES IS RESISTANCE OF THE MATERIAL. IF AN MATERIAL AS NATURE OF RRESTRICTING THE
CURRENT THEN IT IS TERMED AS RESISTOR OTHERWISE CONDUCTOR.
DEFINATION---THE PROPERTY OF OPPOSING ELECTRONS BY AN MATERIAL IS CALLED AS
RESISTANCE, WHICH IS REPRESENTED IN TWO WAYS----EITHER IN TERMS OF RESISTIVITY, LENGTH ,AREA
OR IN TERMS OF VOLTAGE APPLIED AND CURRENT FLO ING THROUGH IT.
PROCESS---TO AN MATERIAL WHEN EXTERNAL PRESSURE IS APPLIED( VOLTAGE) TILL
OT ANODE, DURING THIS TRAVEL ELECTRONS TENDS TO COLLIDE THE ATOMS OF MATERIAL THEIR BY
THEN RANDOMLYJNTUMOVINGELECTRONSTENDSMOVEIN ONE PARTICULAR DIRECTION FROM CATHODE
LOOSING KINETIC ENERGY AND NOT REACHING THE ANODE, THIS IS CALLED AS RESISTANCE, AS
NUMBER OF COLLISIONS INCREASES THE RESISTANCE PROPERTY OF MATERIAL ALSO INCRASES.
DISCRIPTION:
THE MEASUREME
OF RESISTANCE GOT VERY
IMPORTANCE IN POWER SYSTEMS AS IT
PLAYS KEY ROLE IN POWER SYSTEM OPERATION AND CONTROL. DEPENDING ON RANGE MEASUREMENT
OF RESISTANCE IS CLASSIFIED I TO THREE TYPES--1. LOW RANGE RESISTANCE.
2. MEDIUM RANGE RESISTANCE.
3. HIGH RANGE RESISTANCE.
LOW RANGE RESISTANCE:
TO MEASURE LOW RANGE THE DOFFERENT METHODS ARE
1. VOLT-AMP METHOD
2. POTENTIOMETER
3. KE LVIN DOUBLE BRIDGE
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WE SHALL STUDY DEEP INTO THESE METHODS AND CHOOSE WHICH METHOD IS BEST SUITABLE FOR
MEASUREMENT OF RESISTANCE. EVERY METHODS GOT THEIR OWN ADVANTAGES, DISADVANTAGES
AND LIMITATIONS.
MEDIUM RANGE RESISTANCE:
TO MEASURE MEDIUM RANGE THE DOFFERENT METHODS ARE
1. VOLT-AMP METHOD
2. SUBSTITUTION METHOD
3. WHEAT STONE BRIDGE.
WE SHALL STUDY DEEP INTO THESE METHODS AND CHOOSE WHICH METHOD IS BEST SUITABLE FOR
MEASUREMENT OF RESISTANCE. EVERY METHODS GOT THEIR OWN ADVANTAGES, DISADVANTAGES
AND LIMITATIONS.
HIGH RANGE RESISTANCE:
TO MEASURE HIGH RANGE THE DOFFERENT METHODS ARE
1.
2.
3.
4.
5.
VOLT-AMP METHOD
MEGA OHM BRIDGE
OHMMETER.
MEGGER.
LOSS OF CHARGE ME HOD
WE SHALL STUDY DEEP I TO THESE METHODS AND CHOOSE WHICH METHOD IS BEST SUITABLE FOR
MEASUREMENT OF RESISTA CE. EVERY METHODS GOT THEIR OWN ADVANTAGES, DISADVANTAGES
AND LIMITATIO S.
CONCLUSION:
THE DIFFERENT WAYS TO MEASURE RESISTANCE OF MATERIAL UNDER DIFFERENT
CONDITIONS IN THE CHOOSEN ARE MEASURED WITH MOST PRECISIONEDLY . ALSO THE ERROR IN THE
ME SUREMENT OF RESISTANCE USING VARIOUS METHODDS ARE THOROUGHLY ANALYSED HERE AND
BEST METHOD IS SUGGESTED.
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UNIT 7
INTRODUCTION:
THE OTHER TWO PARAMETERS WHICH RULE THE ELECTRICAL ENGINEERING ARE
INDUCTOR AND CAPACITOR.
INDUCTOR IS AN CONSTRUCTION OF
IRE IN THE T
ISTED FORM EXHIBITING
INDUCATNCE PROPERTY, THIS INDUCTOR ELEMENT GOT APPLICATIONS IN DESIGN OF MACHINES FOR
GENERATION, FOR FILTERING, FOR STORING ENERGY ETC.THIS STORES ENERGY IN THE FORM OF
MAGNETIC FIELD.INDUCTOR IS ASSOCIATED WITH STORING FACTOR.
CAPACITOR IS THE CONSTR CTION OF TWO PARALLEL PLATES SEPERATED BY
INSULATION MEDIUM EXHIBITING PROPERTY OF CAPACITANCE, WHICH GOT APPLICATIONS IN POWER
SYSTEM TRANSMISSION AND DIS RIB
ION. HIS STORES ENERGY IN THE FORM OF ELECTRIC
FIELD.CAPACITOR IS ASSOCIA ED WI H LOSS FAC OR.
DISCRIPTION:
HE CE TO MEASURE I DUCTANCE AND CAPACITANCE AC BRIDGES ARE EVOVLED .
AC BRIDGES CO SISTS OF FOUR ARMS, SOURCE AND DETECTOR. EACH ARM IS REPRESENTED WITH
IMPEDANCE. SOURCE IS AN BRIDGE OSCILLATOR , POWER LINE ETC.
MEASUREMENT OF UNKNOWN INDUCTANCE:
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CONSTRUCTION AND DERIVATION OF ALONG WITTH THE PHASOR DIAGARM MAXWELL’S
BRIDGE
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ADAVTAGES AND DISADVANTAGES OF MAXWELL’S BRIDGE
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CONSTRUCTION AND DERIVATION OF ALONG WITTH THE PHASOR DIAGARM HAYS BRIDGE
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ADAVTAGES AND DISADVANTAGES OF HAYS BRIDGE
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CONSTRUCTION AND DERIVATION OF ALONG WITTH THE PHASOR DIAGARM ANDERSON’S
BRIDGE
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ADAVTAGES AND DISADVANTAGES OF ANDERSON’S BRIDGE
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CONSTRUCTION AND DERIVATION OF ALONG WITTH THE PHASOR DIAGARM OWEN’S BRIDGE
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ADAVTAGES AND DISADVANTAGES OF OWEN’S BRIDGE
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MEASUREMENT OF UNKNOWN CAPACITANCE:
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CONSTRUCTION AND DERIVATION OF ALONG WITTH THE PHASOR DIAGARM DESAUTY’S
BRIDGE
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ADAVTAGES AND DISADVANTAGES OF DESAUTY’S BRIDGE
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CONSTRUCTION AND DERIVATION OF ALONG WITTH THE PHASOR DIAGARM WEIN’S BRIDGE
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ADAVTAGES AND DISADVANTAGES OF WEIN’S BRIDGE
CONSTRUCTION AND DERIVATION OF ALONG
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ITTH THE PHASOR DIAGARM SCHERING BRIDGE
ADAVTAGES AND DISADVANTAGES OF SCHERING BRIDGE
CONCLUSION:
THE AC BRIDGES GOT VERY M CH IMPORATNCE IN MEASURING UNKNOWN
PARAMETERS LIKE INDUCATNCE, CAPACIATNCE AND THEIR STORAGE , LOSS FACTOR. OTHER THAN
USING RLC METERS TO MEASURE
HESE PARAMETERS AC BRIDGES ARE COMPARISON METHODS
WHICH GIVES VERY PRECISION VAL E. EVERY BRIDGE GOT THEIR OWN ADVANTAGES AND
DISADVANTAGES TO OVERCOME HAT NEW BRIDGE IS EVOVLED .
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UNIT 8
INTRODUCTION:
OTHER THAN MAJOR MEASURING DEVICES THEIR ARE OTHER DEVICES ALSO WHICH
ARE USED OCCASIONALLY. OUT OF THAT WE ARE GOING TO DEAL WITH BALLASTIC GALVANOMETER
AND FLUXMETER.
DISCRIPTION:
HERE WE SHALL SEE THE DEFINATION OF BALLASTIC GALVANOMETER,
CONSTRUCTION AND OPEARTION BALLASTIC GALVANOMETER, ADVANTAGES OF DISADVANTAGES OF
BALLASTIC GALVANOMETER, EQUATION OF MOTION FOR BALLASTIC GALVANOMETER.
LATER WE SHALL SEETHE
CONSTRUCTION AND OPEARTION OF FLUX METER,
ADVANTAGES OF DISADVANTAGES OF FL X METER.
COMPARISION
BETWEEN
BALLASTIC
GALVANOMETER
FLUXMETER.APPLICATIONS OF BALLAS IC GALVANOMETER AND FLUXMETER
DETERMINATION OF B-H LOOP ME HODS
AC TESTING
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IRON LOSS OF BAR
CORENSTRUCTION LOSS MEASUREMENT
CONCLUSION:
THEERE FOR THE IMPORATNCE OF BALLASTIC GALVANOMETER AND FLUXMETER IN
POWER SYSTEMS ARE STUDIED, AND THEIR IMPORTANCES ARE COMPARED .
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AND