Experimental Methods for Engineers

716 Pages·2000·49.513 MB·English

by  Jack Holman

E M
XPERIMENTAL ETHODS
E
FOR NGINEERS
S E V E N T H E D I T I O N
McGraw-HillSeriesinMechanicalEngineering
CONSULTINGEDITORS
JackP.Holman,SouthernMethodistUniversity
JohnLloyd,MichiganStateUniversity
Anderson Kelly
ComputationalFluidDynamics:TheBasicswithApplications FundamentalsofMechanicalVibrations
Anderson Martin
ModernCompressibleFlow:WithHistoricalPerspective KinematicsandDynamicsofMachines
Arora Mattingly
IntroductiontoOptimumDesign ElementsofGasTurbinePropulsion
BormanandRagland Modest
CombustionEngineering RadiativeHeatTransfer
Cengel Norton
HeatTransfer:APracticalApproach DesignofMachinery
Cengel OosthuizenandCarscallen
IntroductiontoThermodynamics&HeatTransfer CompressibleFluidFlow
CengelandBoles OosthuizenandNaylor
Thermodynamics:AnEngineeringApproach IntroductiontoConvectiveHeatTransferAnalysis
CengelandTurner Reddy
FundamentalsofThermal-FluidSciences AnIntroductiontoFiniteElementMethod
Culp RosenbergandKarnopp
PrinciplesofEnergyConversion IntroductiontoPhysicalSystemsDynamics
Dieter Schlichting
EngineeringDesign:AMaterials&ProcessingApproach BoundaryLayerTheory
Doebelin Shames
EngineeringExperimentation:Planning,Execution,Reporting MechanicsofFluids
Driels ShigleyandUicker
LinearControlSystemsEngineering TheoryofMachinesandMechanisms
EdwardsandMcKee Stoecker
FundamentalsofMechanicalComponentDesign DesignofThermalSystems
Gibson StoeckerandJones
PrinciplesofCompositeMaterialMechanics RefrigerationandAirConditioning
Hamrock Turns
FundamentalsofFluidFilmFabrication AnIntroductiontoCombustion:ConceptsandApplications
Hamrock Ullman
FundamentalsofMachineElements TheMechanicalDesignProcess
Heywood Wark
InternalCombustionEngineFundamentals AdvancedThermodynamicsforEngineers
HistandandAlciatore WarkandRichards
IntroductiontoMechatronicsandMeasurementSystems Thermodynamics
Holman White
ExperimentalMethodsforEngineers FluidMechanics
Jaluria White
DesignandOptimizationofThermalSystems ViscousFluidFlow
KaysandCrawford Zeid
ConvectiveHeatandMassTransfer CAD/CAMTheoryandPractice
E M
XPERIMENTAL ETHODS
E
FOR NGINEERS
S E V E N T H E D I T I O N
J. P. Holman
ProfessorofMechanicalEngineering
SouthernMethodistUniversity
Boston Burr Ridge, IL Dubuque, IA Madison, WI New York San Francisco St. Louis
Bangkok Bogotá Caracas Lisbon London Madrid
Mexico City Milan New Delhi Seoul Singapore Sydney Taipei Toronto
EXPERIMENTALMETHODSFORENGINEERS
PublishedbyMcGraw-Hill,animprintofTheMcGraw-HillCompanies,Inc.,1221Avenueofthe
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Experimentalmethodsforengineers/J.P.Holman.–7thed.
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Includesbibliographicalreferencesandindex.
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A A
BOUT THE UTHOR
J.P.HolmanreceivedhisPh.D.inmechanicalengineeringfromOklahomaStateUni-
versity.AftertwoyearsactivedutyasaresearchscientistintheAirForceAerospace
ResearchLaboratory,hejoinedthefacultyofSouthernMethodistUniversity,where
heispresentlyBrownFoundationProfessorofMechanicalEngineering.Hehasheld
administrativepositionsasDirectoroftheThermalandFluidSciencesCenter,Head
ofCivilandMechanicalEngineeringDepartment,AssistantProvostforInstructional
Media,andhasbeentherecipientoffifteenoutstandingteacherawards.
Dr.Holmanpublishedover30papersinseveralareasofheattransferandhisthree
widelyusedtextbooks,HeatTransfer,1963(8thed.1998),ExperimentalMethodsfor
Engineers,1966(6thed.1994),andThermodynamics,1969(4thed.1988),allpub-
lishedbyMcGraw-Hill,Inc.,havebeentranslatedintoSpanish,Chinese,Japanese,
Korean,Indonesian,andPortugueseandaredistributedworldwide.
A member of the American Society of Engineering Education, Dr. Holman is
pastChairmanoftheNationalMechanicalEngineeringDivisionandpastChairman
oftheASMERegionXMechanicalEngineeringDepartmentHeads.Dr.Holmanis
aregisteredprofessionalengineerinthestateof TexasandreceivedtheMechanical
EngineeroftheYearawardfromtheNorthTexasSectionoftheAmericanSocietyof
MechanicalEngineersin1971.
Dr. Holman is also the recipient of the George Washington Award from the
AmericanSocietyofEngineeringEducationfordistinguishedcontributionstoEngi-
neering Education (1972), the James Harry Potter Gold Medal for contributions to
thermodynamics from ASME (1986), and the Worcester Reed Warner Gold Medal
foroutstandingcontributionstothepermanentliteratureofengineeringfromASME
(1987).HeisaLifeFellowofASME.In1993hewastherecipientoftheLohmann
MedalfromOklahomaStateUniversity,awardedannuallytoadistinguishedalumnus
of that institution. In 1995, Dr. Holman received the Ralph Coats Roe Award from
ASEEforexcellenceinmechanicalengineeringeducation.
v
C
ONTENTS
Chapter 1 3.10 TheChi-SquareTestofGoodnessofFit 84
INTRODUCTION 1 3.11 MethodofLeastSquares 91
3.12 TheCorrelationCoefficient 95
Chapter 2 3.13 MultivariableRegression 96
BASIC CONCEPTS 5 3.14 StandardDeviationoftheMean 98
3.15 Student’st-Distribution 99
2.1 Introduction 5
3.16 GraphicalAnalysisandCurveFitting 106
2.2 DefinitionofTerms 5 3.17 ChoiceofGraphFormats 107
2.3 Calibration 6 3.18 GeneralConsiderationsin
2.4 Standards 7 DataAnalysis 123
2.5 DimensionsandUnits 11 3.19 Summary 124
2.6 TheGeneralizedMeasurementSystem 14 3.20 ReviewQuestions 125
2.7 BasicConceptsinDynamic 3.21 Problems 125
Measurements 18 3.22 References 141
2.8 SystemResponse 31
2.9 Distortion 32 Chapter 4
2.10 ImpedanceMatching 32 BASIC ELECTRICAL MEASUREMENTS
2.11 ExperimentPlanning 35 AND SENSING DEVICES 144
2.12 ReviewQuestions 39
4.1 Introduction 144
2.13 Problems 41
4.2 ForcesofElectromagneticOrigin 144
2.14 References 46
4.3 WaveformMeasures 148
4.4 BasicAnalogMeters 151
Chapter 3
ANALYSIS OF EXPERIMENTAL 4.5 BasicDigitalMeters 157
DATA 48 4.6 BasicInputCircuits 158
4.7 Amplifiers 172
3.1 Introduction 48 4.8 DifferentialAmplifiers 176
3.2 CausesandTypesofExperimental 4.9 OperationalAmplifiers 176
Errors 49 4.10 Transformers 180
3.3 ErrorAnalysisonaCommonsenseBasis 50 4.11 PowerSupplies 182
3.4 UncertaintyAnalysis 51 4.12 SignalConditioning 183
3.5 Evaluation of Uncertainties for Complicated 4.13 TheElectronicVoltmeter(EVM) 194
DataReduction 60 4.14 DigitalVoltmeters 195
3.6 StatisticalAnalysisofExperimental 4.15 TheOscilloscope 197
Data 62 4.16 OscilloscopeSelection 201
3.7 ProbabilityDistributions 67 4.17 OutputRecorders 203
3.8 TheGaussianorNormalError 4.18 Counters—TimeandFrequency
Distribution 71 Measurements 204
3.9 ComparisonofDatawithNormal 4.19 Transducers 204
Distribution 80 4.20 TheVariable-ResistanceTransducer 205
vi
CONTENTS vii
4.21 TheDifferentialTransformer(LVDT) 205 6.7 TheBridgmanGage 271
4.22 CapacitiveTransducers 209 6.8 Low-PressureMeasurement 272
4.23 PiezoelectricTransducers 211 6.9 TheMcLeodGage 272
4.24 PhotoelectricEffects 213 6.10 PiraniThermal-ConductivityGage 274
4.25 PhotoconductiveTransducers 214 6.11 TheKnudsenGage 275
4.26 PhotovoltaicCells 217 6.12 TheIonizationGage 277
4.27 IonizationTransducers 217 6.13 TheAlphatron 278
4.28 MagnetometerSearchCoil 218 6.14 Summary 278
4.29 Hall-EffectTransducers 220 6.15 ReviewQuestions 279
4.30 DigitalDisplacementTransducers 221 6.16 Problems 280
4.31 ComparisonofAnalogandDigital 6.17 References 285
Instruments 222
4.32 Summary 222 Chapter 7
4.33 ReviewQuestions 223 FLOW MEASUREMENT 287
4.34 Problems 224
7.1 Introduction 287
4.35 References 231
7.2 Positive-DisplacementMethods 288
7.3 Flow-ObstructionMethods 291
Chapter 5
7.4 PracticalConsiderationsforObstruction
DISPLACEMENT AND AREA
Meters 295
MEASUREMENTS 233
7.5 TheSonicNozzle 304
5.1 Introduction 233 7.6 FlowMeasurementbyDragEffects 306
5.2 DimensionalMeasurements 233 7.7 Hot-WireandHot-FilmAnemometers 314
5.3 GageBlocks 235 7.8 MagneticFlowmeters 319
5.4 OpticalMethods 236 7.9 Flow-VisualizationMethods 320
5.5 PneumaticDisplacementGage 239 7.10 TheShadowgraph 322
5.6 AreaMeasurements 241 7.11 TheSchlieren 323
5.7 ThePlanimeter,aDeviceofHistorical 7.12 TheInterferometer 326
Interest 242 7.13 TheLaserDopplerAnemometer
5.8 Graphical and Numerical Methods for Area (LDA) 328
Measurement 243 7.14 SmokeMethods 331
5.9 SurfaceAreas 248 7.15 PressureProbes 331
5.10 Problems 249 7.16 ImpactPressureinSupersonicFlow 340
5.11 References 253 7.17 Summary 341
7.18 ReviewQuestions 342
Chapter 6 7.19 Problems 344
PRESSURE MEASUREMENT 255 7.20 References 351
6.1 Introduction 255
Chapter 8
6.2 DynamicResponseConsiderations 258
THE MEASUREMENT OF
6.3 MechanicalPressure-Measurement
TEMPERATURE 355
Devices 260
6.4 Dead-WeightTester 265 8.1 Introduction 355
6.5 Bourdon-TubePressureGage 266 8.2 TemperatureScales 355
6.6 DiaphragmandBellowsGages 267 8.3 TheIdeal-GasThermometer 356
viii CONTENTS
8.4 TemperatureMeasurementbyMechanical 10.3 ElasticElementsforForce
Effects 358 Measurements 465
8.5 TemperatureMeasurementbyElectrical 10.4 TorqueMeasurements 469
Effects 362 10.5 StressandStrain 473
8.6 TemperatureMeasurementby 10.6 StrainMeasurements 474
Radiation 383 10.7 Electrical-ResistanceStrainGages 475
8.7 EffectofHeatTransferonTemperature 10.8 MeasurementofResistanceStrain-Gage
Measurement 390 Outputs 479
8.8 TransientResponseofThermal 10.9 TemperatureCompensation 480
Systems 399 10.10 Strain-GageRosettes 481
8.9 ThermocoupleCompensation 401 10.11 TheUnbondedResistanceStrain
8.10 TemperatureMeasurementsinHigh-Speed Gage 484
Flow 404 10.12 ReviewQuestions 485
8.11 Summary 408 10.13 Problems 486
8.12 ReviewQuestions 408 10.14 References 490
8.13 Problems 409
8.14 References 418 Chapter 11
MOTION AND VIBRATION
Chapter 9 MEASUREMENT 492
THERMAL- AND
11.1 Introduction 492
TRANSPORT-PROPERTY
11.2 TwoSimpleVibrationInstruments 492
MEASUREMENTS 420
11.3 PrinciplesoftheSeismicInstrument 494
9.1 Introduction 420 11.4 PracticalConsiderationsforSeismic
9.2 Thermal-ConductivityMeasurements 421 Instruments 501
9.3 ThermalConductivityofLiquidsand 11.5 SoundMeasurements 504
Gases 425 11.6 ReviewQuestions 517
9.4 MeasurementofViscosity 427 11.7 Problems 518
9.5 GasDiffusion 434 11.8 References 523
9.6 Calorimetry 438
9.7 ConvectionHeat-Transfer Chapter 12
Measurements 442 THERMAL- AND
9.8 HumidityMeasurements 445 NUCLEAR-RADIATION
9.9 Heat-FluxMeters 448 MEASUREMENTS 525
9.10 pHMeasurement 451
12.1 Introduction 525
9.11 ReviewQuestions 452
12.2 DetectionofThermalRadiation 525
9.12 Problems 453
12.3 MeasurementofEmissivity 531
9.13 References 459
12.4 ReflectivityandTransmissivity
Measurements 534
Chapter 10
12.5 SolarRadiationMeasurements 535
FORCE, TORQUE, AND STRAIN
12.6 NuclearRadiation 537
MEASUREMENTS 461
12.7 DetectionofNuclearRadiation 538
10.1 Introduction 461 12.8 TheGeiger-Mu¨llerCounter 538
10.2 MassBalanceMeasurements 462 12.9 IonizationChambers 539
CONTENTS ix
12.10 PhotographicDetectionMethods 540 14.8 Summary 600
12.11 TheScintillationCounter 541 14.9 Glossary 600
12.12 NeutronDetection 541 14.10 ReviewQuestions 602
12.13 StatisticsofCounting 542 14.11 Problems 602
12.14 ReviewQuestions 546 14.12 References 604
12.15 Problems 546
12.16 References 549 Chapter 15
REPORT WRITING AND
Chapter 13 PRESENTATIONS 605
AIR-POLLUTION SAMPLING AND
15.1 Introduction 605
MEASUREMENT 552
15.2 SomeGeneralComments 605
13.1 Introduction 552 15.3 TypesofReports 608
13.2 UnitsforPollutionMeasurement 552 15.4 ContentsofaReport 610
13.3 Air-PollutionStandards 553 15.5 GraphicalPresentations 618
13.4 GeneralAir-SamplingTrain 556 15.6 MiscellaneousHelpfulHints 629
13.5 GasSamplingTechniques 557 15.7 WordProcessorsandComputers 630
13.6 ParticulateSamplingTechniques 558 15.8 ProcessingofReports 631
13.7 SulfurDioxideMeasurements 566 15.9 OralPresentations 633
13.8 CombustionProductsMeasurements 569 15.10 PlanningSessionsandConferences 635
13.9 OpacityMeasurements 573 15.11 ReviewQuestions 636
13.10 OdorMeasurement 574 15.12 References 637
13.11 ReviewQuestions 575
13.12 Problems 576 Chapter 16
13.13 References 577 DESIGN OF EXPERIMENTS 638
16.1 Introduction 638
Chapter 14
16.2 TypesofExperiments 638
DATA ACQUISITION
16.3 ExperimentDesignFactors 642
AND PROCESSING 579
16.4 ExperimentDesignProtocol
14.1 Introduction 579 andExamples 642
14.2 TheGeneralDataAcquisitionSystem 579 16.5 Summary 677
14.3 SignalConditioningRevisited 582 16.6 Problems 678
14.4 DataTransmission 585 16.7 References 679
14.5 Analog-to-DigitalandDigital-to-Analog
Conversion 588 APPENDIX 680
14.6 DataStorageandDisplay 596
14.7 TheProgramasaSubstitute
forWiredLogic 597 INDEX 690
L W E
IST OF ORKED XAMPLES
Example2.1 Stepresponseoffirst-ordersystem
Example2.2 Phaselaginfirst-ordersystem
Example2.3 Harmonicresponseoffirst-ordersystem
Example2.4 Selectionofsecond-ordersystem
Example2.5 Responseofpressuretransducer
Example2.6 Risetimefordifferentnaturalfrequencies
Example2.7 Powersupply
Example3.1 Uncertaintyofresistanceofacopperwire
Example3.2 Uncertaintyinpowermeasurement
Example3.3 Selectionofmeasurementmethod
Example3.4 Instrumentselection
Example3.5 Waystoreduceuncertainties
Example3.6 Uncertaintycalculationbyresultperturbation
Example3.7 Calculationofpopulationvariables
Example3.8 Samplestandarddeviation
Example3.9 Tossingacoin—binomialdistribution
Example3.10 Probabilityfordeviationfrommeanvalue
Example3.11 Determinationofnumberofmeasurementstoassureasignificancelevel
Example3.12 Powersupply
Example3.13 ApplicationofChauvenet’scriterion
Example3.14 Useofprobabilitygraphpaperandcomputercomparison
Example3.15 Defectsinplasticcups
Example3.16 Rollingthedice
Example3.17 Tossofcoin:Influenceofadditionaldatapoints
Example3.18 Effectofcigarettesmokeonmice
Example3.19 Least-squaresregression
Example3.20 Correlationcoefficient
Example3.21 Uncertaintyinmeanvalue
Example3.22 Confidencelevelfromt-distribution
Example3.23 Estimateofsamplesize
Example3.24 Confidencelevel
Example3.25 Confidencelevel
Example3.26 Lowerconfidencelevel
Example3.27 Trade-offinnumberofmeasurements
Example3.28 Comparisonoftwosamples
Example3.29 Correlationofdatawithpowerrelation
Example3.30 Alternativedisplaysandcorrelationtrendlinesforexponentialfunction
Example3.31 Evolutionofacorrelationusingcomputergraphics
Example3.32 Correlationtrendlinesusingoffsetpoints
x