EGR 2042INSTRUMENTATION & MEASUREMENTChapter 1:Introduction to Instrumentation Chapter 2: DC & AC meter measurement Chapter 3:Oscilloscope Chapter 4:Signal Generator Chapter 5:Transducer
* Modern Electronic Instrumentation and Measurement Techniques, Albert D Helfrick & William D Cooper, Prentice Hall. Elements of Electronic Instrumentation and Measuerement, Joseph J Carr, Prentice Hall. Principles of Electronic Instrumentation and Measurement, Howard M Berlin & Frank C Getz Jr., Macmillan.Siti Hajar Binti Md AzizFakulti TelekumunikasiKolej Multimedia2012
DEFINITIONInstrumentation is a technology of measurement which serves not only science but all branches of engineering, medicine, and almost every human endeavor.Or A device or mechanism used to determine the present value of the quantity under measurement.
Electronic Instrumentation the application of measurement technology in Electronic-related field.
*Hot/Coldthermometer35 0C
Measurement: The process of determining the amount, degree, or capacity by comparison (direct or indirect) with accepted standard of the system units being used.
Measurementi-Simple measurement hot/cold thermometer350C
ii-Complex measurementhot/cold thermocouple amplifier 35 0C
Static measurement: are used to measure an unvarying process condition.
Dynamic measurement: involves changing times*
Instrumenti-analog view is shown by the movement or deflection of null pointer
ii-digital display in numeric form
*Chapter 1 Introduction to Instrumentation
STATIC CHARACTERISTICSExpected value: the design value, i.e. the most probable value that calculations indicate one should except to measure.Error: the deviation of the true value from the desired value.Accuracy: the degree of exactness (closeness) of a measurement compared to the expected (desired value)Precision: A measure of the consistency or repeatability of measurement, i.e. successive reading do not differ. (precision is the consistency of the instrument output for a given value of input)Sensitivity: The ratio of the change in output (response) of the instrument to a change of input or measured variable.
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CHAPTER 1INTRODUCTION TO INSTRUMENTATIONStandard MeasurementStandard : physical representation units of measurement(used for calculate the value of a physical quantity, the others by means of comparison)SI (International System) > Mechanical Uniti. length : meter (m)ii. mass : kilogram (kg) > Electrical Uniti. Arus : Ampere (A)ii. Voltan : Volt (v)*
MEASUREMENT STANDARDS*Measurement StandardsInternational StandardsPrimary StandardsSecondary StandardsWorking Standards
International Standards- Defined by international agreements, and are maintained at the International Bureau of Weight & Measures in France.-and may be used for checking primary standards.
Primary Standards- more accurate than secondary standards.- they are maintained to the highest possible accuracy by national institutions as references for calibrating secondary standards. Example: SIRIM*
iii.Secondary Standards-are used throughout industry for checking working standards and for calibrating high accuracy equipment.- more accurate than working standards.
iv.Working Standards- are used as measurement references on day to day basis in virtually all electronic laboratories.*
MEASUREMENT UNITS*
QuantityUnitSymbolLength (l)metermTime (t)secondsMass (m)kilogramkgCurrent (I)ampereATemperature (T)kelvinK
MEASUREMENT UNITS*
QuantityUnitSymbolValueFrequencyHertzHzs-1VelocityMeter/secondm.s-1AccelerationMeter/second-squaredm.s-2ForceNewtonNKg.m.s-2EnergyJouleJN.mPowerWattWJ.s-1Electric CircuitAmpereAElectric ChargeCoulombCA.s
MEASUREMENT UNITS*
VoltageVoltVJ.C-1Electric FieldVolt/meterV.m-1ResistanceOhmV.A-1ResistivityOhm.meter.mConductanceSiemensS-1ConductivitySiemens/meterS.m-1CapacitanceFaradFC.V-1Magnetic Flux LinkageWeberWbV.sMagnetic Flux DensityTeslaTWb.m-2InductanceHenryHWb.A-1
MEASUREMENT ERRORSNO ELECTRONIC OR INSTRUMENT IS PERFECTLY ACCURATE, ALL HAVE SOME ERROR OR INACCURACY.
Types of ErrorGross Error : Are essentially human errors that are the result of carelessness. Ex: misreading of an instrument.Systematic Error : Apart from equipment error, some operator or observer error is inevitable.Random Error: unexplainable origin.*
MEASUREMENT ERRORS
Absolute Error: possible errorEx: If a resistor is known have a resistance of 500 with a possible error of 50, the 50is an absolute error.
* This is because 50 is stated as an absolute quantity, not as a percentage of 500 resistance. Relative Error: when the error is expressed as a percentage or as a fraction of the total resistance, it becomes a relative error.Ex: the 50 is 10%, relative to 500 , or 1/10 of 500 .R= 500 10%
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e = Yn Xn
where;e : absolute errorYn : expected valueXn : measured value
% Error = (e / Yn) x 100 %
Relative accuracy, A = 1 (e / Yn)
% Accuracy, a = 100 % - % error
Precision = 1 [(Xn Xn) / Xn]where;Xn : the measurement of the nthXn : average of n measurements*
EXAMPLE 1The expected value of the voltage across a resistor is 80 V. However, the measurement gives a value of 79 V. Calculate:
a) absolute errorb) % errorc) relative accuracy, andd) % of accuracy.
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*Example 2:
Table below gives the set of 10 measurement that were recorded in the laboratory. Calculate the precision of the 6th measurement.
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Elemen Peralatan Elektronik
- Transduser mengubah isyarat bukan-elektrik kpd isyarat elektrik cth: termocouple
- Pengubah isyarat memproses isyarat elektrik yg diterima supaya ia lebih sesuai utk aplikasi peranti penunjuk
- Peranti penunjuk jenis pesongan atau jenis perpuluhan
Transduser Pengubah isyarat Peranti penunjuk*
Thank you for your attention..*
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