measurement instrumentation and sensors handbook spatial mechanical thermal and radiation measurement second edition pdf

Contents Preface xiii Acknowledgments xv Editorsxvii Contributorsxix Part I Instrumentation and Measurement Concepts... 1.1 Introduction Measurement is a process of gathering information

Spatial, Mechanical, Thermal,

CRC Press is an imprint of the

Taylor & Francis Group, an informa business

Boca Raton London New York

Spatial, Mechanical, Thermal,

MATLAB® is a trademark of The MathWorks, Inc and is used with permission The MathWorks does not warrant the accuracy of the text or exercises in this book This book’s use or discussion of MATLAB® software or related products does not constitute endorsement or sponsorship by The MathWorks of a particular pedagogical approach or particular use of the MATLAB® software.

CRC Press

Taylor & Francis Group

6000 Broken Sound Parkway NW, Suite 300

Boca Raton, FL 33487-2742

© 2014 by Taylor & Francis Group, LLC

CRC Press is an imprint of Taylor & Francis Group, an Informa business

No claim to original U.S Government works

Version Date: 20130725

International Standard Book Number-13: 978-1-4398-4889-0 (eBook - PDF)

This book contains information obtained from authentic and highly regarded sources Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the valid- ity of all materials or the consequences of their use The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint.

Except as permitted under U.S Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or lized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopy- ing, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers.

uti-For permission to photocopy or use material electronically from this work, please access www.copyright.com (http:// www.copyright.com/) or contact the Copyright Clearance Center, Inc (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged.

Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for

identification and explanation without intent to infringe.

Visit the Taylor & Francis Web site at

http://www.taylorandfrancis.com

and the CRC Press Web site at

http://www.crcpress.com

Contents

Preface xiii Acknowledgments xv Editorsxvii Contributorsxix

Part I Instrumentation and Measurement Concepts

Thehandbookcoversanextensiverangeoftopicsthatcomprisethesubjectofmeasurement,instru-Thechaptersincludedescriptiveinformationforprofessionals,students,andworkersinterestedinmeasurementTheyincludeequationstoassistengineersandscientistswhoseektodiscoverapplica-tionsandsolveproblemsthatariseinfieldsnotintheirspecialtyTheyalsoincludespecializedinforma-tionneededbyinformedspecialistswhoseektolearnadvancedapplicationsofthesubject,evaluativeopinions,andpossibleareasforfuturestudyThus,thehandbookservesthereferenceneedsofthebroadestgroupofusers—fromtheadvancedhigh-schoolsciencestudenttoindustrialanduniversityprofessionals

Organization

Inthisedition,thefirstvolumehas10parts,eachhavingseveralchapters,foratotalof96chapters

writtenbyexpertsintheirareasItconcentratesonconceptsininstrumentationandmeasurements,spatialvariablemeasurement,displacementmeasurement,mechanicalvariablemeasurement,acous-tics,flowand spotvelocity,thermalandtemperaturemeasurement,andradiationItreflectsrecenttrendsininstrumentationandmeasurementswiththeadditionofanewpartonwirelessinstrumenta-tionConceptsincontrolsystemsandhumanfactorsaregivenasaseparatepart

Thesecondvolumehas10parts,eachhavingseveralchapters,foratotalof96chapterswrittenbyexpertsintheirareasasinvolume1Itconcentratesonsensorsandsensortechnology,electricvariablemeasurement,electromagneticvariables,timeandfrequency,opticalmeasurement,chemicalvariables,

xiv Preface

medical,biomedicalandhealth,andenvironmentalmeasurementSignalprocessing,anddisplaysandrecordersconstitutethelasttwopartsofthisvolume

Locating Your topic

Tofindouthowtomeasureagivenvariable,skimthetableofcontents,turntothatsection,andfindthechaptersthatdescribedifferentmethodsofmakingthemeasurementConsiderthealternativemethodsofmakingthemeasurementandeachoftheiradvantagesanddisadvantagesSelectamethod,sensor,andsignalprocessingmethodManychapterslistanumberofvendorstocontactformoreinformationYoucanalsovisithttp://wwwglobalspeccom/toobtainalistofvendors

For more detailed information, consult the index, since certain principles of measurement mayappearinmorethanonechapter

MATLAB®isaregisteredtrademarkofTheMathWorks,IncForproductinformation,pleasecontact:TheMathWorks,Inc

Acknowledgments

Wewouldliketothankalltheauthorsfortheirvaluablecontributiontowardthistwo-volumesetbookWeappreciatethetimeandeffortdevotedbyallournewauthorsandthoseauthorswhowentanextramiletoreviseandupdatetheirchaptersWearegratefultotheCRCPressteamfortheirencouragementtopreparethissecondeditionThepublicationofthisbookwouldnothavebeenpossiblewithouttheirtirelessdedicationinputtingittogetherLastbutnotleast,wewouldliketothankallourreadersinselectingthisbookforadvancingtheirknowledgeandtechnicalskills

John.G Webster.and.Halit.Eren

Co-Editors

Editors

John.G WebsterreceivedhisBEEfromCornellUniversity,Ithaca,NewYork,in1953,andhisMSEE

andPhDfromtheUniversityofRochester,Rochester,NewYork,in1965and1967,respectivelyHeisprofessoremeritusofbiomedicalengineeringattheUniversityofWisconsin–MadisonHeisahighlycitedresearcheratKingAbdulazizUniversity,Jeddah,SaudiArabiaInthefieldofmedicalinstrumentation, heteaches undergraduate and graduate courses and does research onintracranialpressuremonitors,ECGdryelectrodes,andtactilevibrators

DrWebsteristheauthorofTransducers.and.Sensors,.an.IEEE/EAB.Individual.Learning.Program (Piscataway,NJ:IEEE,1989)Heisthecoauthor,withBJacobson,ofMedicine.and.Clinical.Engineering (EnglewoodCliffs,NJ:Prentice-Hall,1977)and,withRPallas-Areny,ofSensors.and.Signal.Conditioning, Second Edition (NewYork:Wiley,2001), andAnalog Signal Conditioning (New York: Wiley, 1999) HeistheeditorofEncyclopedia.of.Medical.Devices.and.Instrumentation,SecondEdition(NewYork: Wiley,2006),Tactile.Sensors.for.Robotics.and.Medicine(NewYork:Wiley,1988),Electrical.Impedance Tomography(Bristol,UK:AdamHilger,1990),Teaching.Design.in.Electrical.Engineering(Piscataway, NJ:EducationalActivitiesBoard,IEEE,1990),Prevention.of.Pressure.Sores:.Engineering.and.Clinical Aspects(Bristol,UK:AdamHilger,1991),Design.of.Cardiac.Pacemakers(Piscataway,NJ:IEEEPress, 1995), Design of Pulse Oximeters (Bristol, UK: IOP Publishing, 1997), Medical Instrumentation: Application and Design, Fourth Edition (Hoboken NJ: Wiley, 2010), Encyclopedia of Electrical and Electronics.Engineering(NewYork,Wiley,1999),Minimally.Invasive.Medical.Technology(Bristol,UK: IOPPublishing,2001),andBioinstrumentation(HobokenNJ:Wiley,2004)Heisthecoeditor,withA MCook,ofClinical.Engineering:.Principles.and.Practices(EnglewoodCliffs,NJ:Prentice-Hall,1979) andTherapeutic.Medical.Devices:.Application.and.Design(EnglewoodCliffs,NJ:Prentice-Hall,1982), withWJTompkinsofDesign.of.Microcomputer-Based.Medical.Instrumentation(EnglewoodCliffs,NJ: Prentice-Hall,1981)andInterfacing.Sensors.to.the.IBM.PC(EnglewoodCliffs,NJ:PrenticeHall,1988), and,withAMCook,WJTompkins,andGCVanderheiden,ofElectronic.Devices.for.Rehabilitation

(London,UK:Chapman&Hall,1985)

DrWebsterhasbeenamemberoftheIEEE-EMBSAdministrativeCommitteeandtheNIHSurgeryandBioengineeringStudySectionHeisafellowoftheInstituteofElectricalandElectronicsEngineers,theInstrumentSocietyofAmerica,theAmericanInstituteofMedicalandBiologicalEngineering,theBiomedicalEngineeringSociety,andtheInstituteofPhysicsHeistherecipientoftheIEEEEMBSCareerAchievementAward

Halit.ErenreceivedhisBEngin1973,MEngin1975,andPhDin1978fromtheUniversityofSheffield,

UnitedKingdomHeobtainedanMBAfromCurtinUniversityin1999

Afterhisgraduation,DrErenworkedinEtibank(aminingandmetallurgycompanyinTurkey)asaninstrumentationengineerfortwoyearsHewasanassistantprofessoratHacettepeUniversityin1980–1981andMiddleEastTechnicalUniversityin1982HehasbeenatCurtinUniversitysince

xviii Editors

1983, researching and teaching primarily in the areas of control systems, instrumentation, andengineeringmanagement

DrErenwasappointedasvisitingassociateprofessoratthePolytechnicUniversityinHongKongin2004andiscurrentlyavisitingprofessorattheUniversityofWisconsin,USAHeisaseniormemberofIEEE,takingrolesinRegion10activities,variouscommitteesfororganizingconferences,andasamem-berofeditorshipintransactionsDrErenhasover180publicationsinconferenceproceedings,books,

andtransactionsHeistheauthorofElectronic.Portable.Instruments—Design.and.Applications(Boca Raton,FL:CRCPress,2004)andWireless.Sensors.and.Instruments—Networks,.Design.and.Applications (BocaRaton,FL:CRCPress,2006)Hehascoedited,withBelaLiptak,Instruments.Engineers’.Handbook— Process.Software.and.Digital.Networks,Vol3,edn4(BocaRaton,FL:CRCPress,2011)Heisinvolved

inwritinganumberofbooksinthefieldofinstrumentationandmeasurementDrErenisactiveinresearchingandpublishingonintelligentsensors,wirelessinstrumentation,wirelesssensornetworks,automationandcontrolsystems,andverylargecontrolsystems

Amit.Bandyopadhyay

DepartmentofCeramicScienceand

EngineeringRutgersUniversityPiscataway,NewJersey

Partha.P Banerjee

DepartmentofElectricalandComputer

EngineeringUniversityofAlabamaatHuntsvilleHuntsville,Alabama

William.H Bayles,.Jr.

TheFredericksCompanyHuntingtonValley,Pennsylvania

Ben.Benhabib

DepartmentofMechanicalandIndustrialEngineering

UniversityofTorontoToronto,Ontario,Canada

Vikram.Bhatia

VirginiaTechBlacksburg,Virginia

A Bonen

UniversityofTorontoToronto,Ontario,Canada

Contributors

IonizingRadiationDivisionPhysicsLaboratory

NationalInstituteofStandardsand

TechnologyGaithersburg,Maryland

Brian.Culshaw

DepartmentofElectronicandElectrical

EngineeringUniversityofStrathclydeGlasgow,England

G Mark.Cushman

GoddardSpaceFlight CenterNationalAeronauticsandSpace

AdministrationGreenbelt,Maryland

Ronald.H Dieck

Pratt&Whitneyand

RonDieckAssociates,Inc

PalmBeachGardens,Florida

Thomas.E Diller

VirginiaTechBlacksburg,Virginia

Madhu.S Dixit

CentreforResearchinParticlePhysicsCarletonUniversity

Ottawa,Ontario,Canada

DepartmentofElectronicEngineeringGunmaUniversity

Mauro.Giaconi

DepartmentofElectronicEngineeringUniversityofRome“TorVergata”

Ronald.T Green

SouthwestResearchInstituteSanAntonio,Texas

Steven.M Grimes

DepartmentofPhysicsandAstronomyOhioUniversity

Athens,Ohio

Reinhard.Haak

UniversityofErlangen–NuernbergErlangen,Germany

John.R Hansman,.Jr.

DepartmentofAeronauticsandAstronauticsMassachusettsInstituteofTechnologyCambridge,Massachusetts

DepartmentofSensorandEWSystemsSwedishDefenceResearchAgencyLinköping,Sweden

Sam.S Khalilieh

DepartmentofElectricalEngineeringEarthTech

GrandRapids,Michigan

Andrei.Kholkine

RutgersUniversityPiscataway,NewJersey

John.A Kleppe

DepartmentofElectricalandBiomedicalEngineering

UniversityofNevada,RenoReno,Nevada

M Kostic

NorthernIllinoisUniversityDeKalb,Illinois

Hans.Mes

CentreforResearchinParticlePhysicsCarletonUniversity

Ottawa,Ontario,Canada

Jaroslaw.Mikielewicz

InstituteofFluidFlowMachineryGdansk,Poland

Harold.M Miller

DataIndustrialCorporationMattapoisett,Massachusetts

Mark.A Miller

NavalResearchLaboratoryWashington,DistrictofColumbia

Roger.Morgan

SchoolofEngineeringLiverpoolJohnMooresUniversityLiverpool,England

Steven.A Murray

UniversityofSanDiegoSanDiego,California

Thomas.Newe

UniversityofLimerickLimerick,Ireland

J.V Nicholas

TemperatureStandardsSectionMeasurementStandardsLaboratoryof

New ZealandLowerHutt,NewZealand

Seiji.Nishifuji

DepartmentofElectricalandElectronic

EngineeringYamaguchiUniversityUbe,Japan

David.S Nyce

RevolutionSensorCompanyCary,NorthCarolina

Italcertifer,Inc

andDepartmentofElectronicEngineeringUniversityofRome“TorVergata”

Rome,Italy

Per.Rasmussen

GRASSoundandVibrationVedback,Denmark

R.P Reed

ProteunServicesAlbuquerque,NewMexico

Herbert.M Runciman

PilkingtonOptronicsScotland,UnitedKingdom

Ricardo.E Saad

HarmonicsLightwavesSunnyvale,California

Ahmad.Safari

DepartmentofCeramicScienceandEngineeringRutgersUniversity

Piscataway,NewJersey

Adelio.Salsano

Italcertifer,Inc

andDepartmentofElectronicEngineeringUniversityofRome“TorVergata”

Rome,Italy

Robert.J Sandberg

DepartmentofMechanicalEngineeringUniversityofWisconsin–MadisonMadison,Wisconsin

Meyer.Sapoff

MSConsultantsPrinceton,NewJersey

DepartmentofElectronicEngineeringGunmaUniversity

Kiryu,Japan

David.B Thiessen

CaliforniaInstituteofTechnologyPasadena,California

Richard.Thorn

SchoolofEngineeringUniversityofDerbyDerby,UnitedKingdom

Hans-Peter.Vaterlaus

DepartmentofInstrumentRittmeyerLtd

Zug,Switzerland

James.H Vignos

TheFoxboroCompanyFoxboro,Massachusetts

London,England

Anbo.Wang

BradleyDepartmentofElectricalEngineeringVirginiaTech

Bernhard.Günther.Zagar

DepartmentofElectricalEngineeringTechnicalUniversityofGraz

Graz,Austria

I Instrumentation

and Measurement

Concepts

. 1 Measurements,.Instrumentation,.and.Sensors Halit.Eren 1-1

Introduction • Measurements • 13 Instruments • AnalogandDigital

Instruments • SensorsandTransducers • InstrumentationandNetworks • Software

SupportforSensorsandInstruments • ApplicationExamples • Bibliography • Partial ListofVendorsandSuppliers

. 2 Characteristics.of.Instrumentation John.R Hansman,.Jr 2-1

SimpleInstrumentModel • Bibliography

. 3 Operational.Modes.of.Instrumentation Richard.S Figliola 3-1

NullInstrument • DeflectionInstrument • AnalogandDigitalSensors • Analog

andDigitalReadoutInstruments • InputImpedance • DefiningTerms • Further

UncertaintyModel • CalculationofExpandedUncertainty • Summary • Defining

Terms • References • FurtherInformation

. 6 Development.of.Standards Halit.Eren 6-1

Introduction • StandardOrganizations • DevelopmentofStandards • Obtainingand UsingStandards • ExamplesofStandards • SoftwareStandards • Bibliography

. 7 Measurement.Standards DeWayne.B Sharp 7-1

HistoricalPerspective • WhatAreStandards? • ConceptualBasisof

Measurements • NeedforStandards • TypesofStandards • Numbers,Dimensions,

andUnits • MultiplicationFactors • ConversionsofUnits • ExamplesofDefining

Terms •Bibliography

I-2 Instrumentation and Measurement Concepts

. 8 Calibrations.in.Instrumentation.and.Measurements Halit.Eren 8-1

Introduction • ErrorsandUncertaintiesinCalibrations • Benefits

ofCalibrations • CalibrationProcedureandPersonnel • Calibration

Methods • LaboratoriesandInstitutions • CalibrationSoftwareSupport • Costof

Calibrations • TrendsinCalibrations • CalibrationExamples • Bibliography • Partial ListofCalibrationServiceandSoftwareProviders

. 9 Intelligent.Sensors.and.Instruments Halit.Eren 9-1

Introduction • IntelligentSensors • TheIEEE1451Standard • Communications

ofIntelligentSensors • Plug-and-PlayCapability • ApplicationsandExamples

ofIntelligentSensors • IntelligentInstruments • ExamplesofIntelligent

Instruments • References • Bibliography • PartialListofManufacturers/Suppliers

. 10 Virtual.Instruments David.Potter.and.Halit.Eren 10-1

Introduction • VirtualInstrumentArchitecture • Virtual InstrumentSoftware •

SupervisoryControlandDataAcquisition • Conclusions • Bibliography • PartialList

Introduction • ProblemsandSolutionsofDynamicCalibrations • Evaluation

ofDynamicCharacteristicsofForceSensors • ImpulseResponse • Oscillation

Response • Conclusions • References

1.1 Introduction

Measurement is a process of gathering information from a physical world and comparing thisinformation with agreed standards As highlighted in this chapter and discussed in detail inthis book,measurementsareessentialactivitiesforobservingandtestingscientificandtechnologi-calinvestigations

Measurementsarecarriedoutbyusinginstruments,whicharedesignedandmanufacturedtofulfillspecifictasksSensorsareusedastheprimaryelementsininstrumentstorespondtothephysical variable under investigation In this book, a diverse range of sensors and instrumentsarediscussed;theadvancesandtherecentdevelopmentsinmeasurements,instrumentation,and

sensorsareintroducedintheproceedingsectionsandchapters

cessunderinvestigationTheseinstrumentsareconnectedtogetherusingwired,optical,orwirelessnetworksThedetailsofthesupportinghardwareandsoftwaretechnologiesbehindthesenetworksarediscussedextensively

Inmanyapplications,manysensorsandinstrumentsareusedtocollectinformationaboutthepro-1

Measurements, Instrumentation,

and Sensors

11 Introduction 1-1 12 Measurements 1-2 13 Instruments 1-2

DesignofInstruments • TestingandUseof Instruments •  ResponseandDrift • AccuracyandErrors • Error

Halit Eren

Curtin University

1-2 Instrumentation and Measurement Concepts

1.2 Measurements

Ifthebehaviorofthephysicalvariableisknown,itsperformancecanbemonitoredandassessedbymeansofsuitablemethodsofsensing,signalconditioning,andterminationTheapplicationsofinstru-mentsrangefromlaboratoryconditionstoarduousenvironmentssuchasinsidenuclearreactorsorremotelocationssuchassatellitesystemsandspaceships

Thesensor-outputsignalsofthemajorityofmoderninstrumentsareinelectricformThisisduetoelectricsignalsbeingeasytoprocess,display,store,andtransmitOnceconvertedtoelectricforms,the

relationbetweenthesensorsignalsandthephysicalvariationscanbeexpressedintheformoftransfer functionsThetransferfunctionisamathematicalmodelbetweenthesensorsignalandthephysical

variableInacontinuoussystem,thetransferfunctionmaybelinearornonlinearAlinearrelationshipmaybeexpressedbythefollowingequation:

• Imperfectionsinelectricandmechanicalcomponents(eg,hightolerancesandnoiseoroffsetvoltages)

• Changesincomponentperformances(eg,shiftingains,changesinchemistry,aging,anddriftsinoffsets)

• Externalandambientinfluences(eg,temperature,pressure,andhumidity)

• Inherentphysicalfundamentallaws(eg,thermalandotherelectricnoises,Brownianmotioninmaterials,andradiation)

mationaboutthemeasurementsanddrawconclusionsDataanalysismayincludestatisticalmethods,curvefitting,selectingordiscardingsubsetsofdata,ormanyothertechniquesForexample,atypicaldataanalysistoolisthedatamining,whichaimstodiscoverunforeseenpatternshiddeninthedataThereisanextensiverangeofsoftwareavailablefortheanalysis(eg,MATLAB®)tosuitspecificneedsofinformationobtainedfromexperimentalortestresultsFurtherinformationonmeasurementsandanalysiscanbefoundthroughoutthisbook

Oncethemeasurementsaremade,variousformsofdataanalysismaybeusedtoextractusefulinfor-1.3 Instruments

Instruments are man-made devices for determining the value of the quantity/variable They aredesignedtomaintainprescribedrelationshipsbetweentheparametersbeingmeasuredandthephysi-calvariablesunderinvestigationInstrumentscanbedesignedandconstructedtobeanalog,digital,orhybrid

Theconstructionofaninstrumentcanbebrokenintosmallerelements,asillustratedinFigure11Typically,aninstrumentwillhaveasensorortransducerstage,asignal-conditioningstage,andanout-putorterminationstageAllinstrumentshavesomeorallofthesefunctionalblocks

Measurements, Instrumentation, and Sensors

AdiverserangeofsensorsandtransducersmaybeavailabletomeetthemeasurementrequirementsofaphysicalsystemThesensorscanbecategorizedinanumberofwaysdependingontheenergyinputandoutput,inputvariables,sensingelements,andelectricorphysicalprinciples

Inrecentyears,therapidgrowthoftheintegratedcircuit(IC)electronicsandtheavailabilityofcost-effectiveprocessorshaveledtoanimpressiveprogressininstrumentationandmeasurementsinallfieldsThiscoupledwiththeimprovementofmathematicalmethods,theextensiveapplica-tionsofdigitaltechniques,andtheadditionofnewapplicationareasenabledmoderninstruments

toexceltonewheightsasdiscussedindetailinthistwo-volumeMeasurements,.Instrumentation, and.Sensors.Handbook

1.3.1 Design of Instruments

encesofpeopleaboutthephysicalprocessorfromstructuredunderstandingoftheprocessInanycase,ideasconceivedaboutaninstrumentaretranslatedintohardwareandsoftwarethatcanperformwellwithintheexpectedstandardsandeasilybeacceptedbytheendusers

Instrumentsaredesignedonthebasisofexistingknowledge,whichisgainedeitherfromtheexperi-Usually, the design of instruments requires many multidisciplinary activities In the wake of a

rapidlychangingtechnology,instrumentsareupgradedoftentomeetthedemandsofthemarketplaceDependingonthecomplexityoftheproposedinstrument,itmaytakemanyyearstoproduceaninstru-mentforarelativelyshortcommerciallifetimeInthedesignandproductionstages,engineersmustconsiderfactorssuchassimplicity,appearance,easeandflexibilityofuse,maintenancerequirements,productioncosts,leadtimetoproduct,andpositioningstrategyinthemarketplace

Thedesignprocessofaninstrumentmayfollowwell-orderedproceduresfromideastomarketingofthefinalproductsTheprocessmaybebrokendownintosmallertaskssuchasidentifyingspecifica-tions,developingpossiblesolutionsforthesespecifications,modeling,prototyping,installingandtest-ing,makingmodifications,manufacturing,planningmarketinganddistribution,evaluatingcustomerfeedback,andmakingdesignandtechnologicalimprovementsForexample,manydifferentspecifica-tionsmaybeconsideredforparticularproduct,whichmayincludebutarenotlimitedtooperationalrequirements,functionality,technologicallimitations,quality,installation,maintenance,documenta-tion,servicing,andacceptancelevelusagebycustomers

1.3.2 testing and Use of Instruments

Aftertheinstrumentisdesignedandprototyped,variousevaluationtestsmaybeconductedThesetestsmaybemadeunderreferenceconditionsorundersimulatedenvironmentalconditionsSomeexamplesofreferenceconditiontestsareaccuracy,responsetime,drift,andwarm-uptimeSimulatedenviron-mentaltestsmaybecompulsory,beingregulatedbygovernmentsandotherauthoritiesSomesimulatedenvironmenttestsincludeclimatictest,droptest,dusttest,insulation-resistancetest,vibrationtest,electromagneticcompatibilitytests,andsafetyandhealthhazardtestsManyofthesearestrictlyregu-latedbynationalandinternationalstandards

Formaximumefficiency,anappropriateinstrumentforthemeasurementmustbeselectedUsersshouldbefullyawareoftheirapplicationrequirements,sinceinstrumentsthatdonotfittheirpur-poseswilldeliverfalsedataresultinginwastedtimeandeffortForaparticularapplication,usersmust

Sensor and/or transducer

Physical

Transmission or display

Excitation

Signal

Output

FIGURE.1.1 Constructionstructureofatypicalinstrument

1-4 Instrumentation and Measurement Concepts

carefully study the documents about all the candidates and make comparisons among all optionsWhile selectingtheinstrument,usersmustevaluatemanyfactorssuchasaccuracy,frequencyresponse,electric and physical loading effects, sensitivity, response time, calibration intervals, power supplyneeds,spareparts,technology,andmaintenancerequirementsTheymustensurecompatibilitywiththeexistingequipment

Whenselectingandimplementingofinstruments,qualitybecomesanimportantissuefrombothquantitative and qualitative perspectives The quality of an instrument may be viewed differentlydependingonthepeopleinvolvedForexample,qualityintheeyesofdesignermaybeaninstrumentdesignedonsoundphysicalprinciples,whereasfromtheusers’pointofview,itmaybereliability,main-tainability,cost,andavailability

1.3.3 response and Drift

InstrumentsrespondtophysicalphenomenonbysensingandgeneratingsignalsDependingonthetypeofinstrumentusedandthephysicalphenomenon,thesignalsmaybeeithersloworfasttochangeandmayalsocontaintransientsTheresponseoftheinstrumentstothesignalscanbeanalyzedinanumberofwaysbyestablishingstaticanddynamicperformancecharacteristicsAlthoughthestaticperformancesarerelativelysimple,thedynamicperformancesmaybecomplexMoreinformationonthiscanbefoundinChapters4,11,and12

1.3.4 accuracy and Errors

TheperformanceofaninstrumentdependsonitsstaticanddynamiccharacteristicsTheperformance

maybeindicatedbyitsaccuracy,whichmaybedescribedastheclosenessofmeasuredvaluestothereal

valuesofthevariableThetotalresponseisacombinationofdynamicandstaticresponsesIfthesignalsgeneratedbythephysicalvariablearechangingrapidly,thenthedynamicpropertiesoftheinstrumentbecomeimportantForslow-varyingsystems,thedynamicerrorsmaybeneglectedFurtherinforma-tiononaccuracycanbefoundinChapter5

Theperformanceofaninstrumentmayalsobedecidedbyotherfactors,suchasthemagnitudesof

errors;therepeatability,whichindicatestheclosenessofsetsofmeasurementsmadeintheshortterm; andthereproducibilityoftheinstrumentThereproducibilityistheclosenessofsetsofmeasurements

whenrepeatedinsimilarconditionsoveralongperiodoftime

The ideal or perfect instrument would have perfect sensitivity, reliability, and repeatabilitywithout any spread of values and would be within the applicable standards However, in manycases,therewillbeimpreciseandinaccurateresultsbecauseofinternalandexternalfactorsThe

departure from the expected perfection is called the error Often, sensitivity analyses are

con-ductedtoevaluatetheeffectofindividualcomponentsthatarecausingtheseerrorsSensitivitytotheaffectingparametercanbeobtainedbyvaryingthatoneparameterandkeepingtheothers

constantThiscanbedonepracticallybyusingthedevelopedinstrumentsormathematicallybymeansofappropriate models

Whendeterminingtheperformanceofaninstrument,itisessentialtoappreciatehowerrorsariseTheremaybemanysourcesoferrors;therefore,itisimportanttoidentifythesesourcesanddrawupanerrorbudgetIntheerrorbudget,theremaybemanyfactors,suchas(1)imperfectionsinelectricandmechanicalcomponents(eg,hightolerancesandnoiseoroffsetvoltages),(2)changesincomponentperformances(eg,shiftingains,changesinchemistry,aging,anddriftsinoffsets),(3) external and ambient influences (eg, temperature, pressure, and humidity), and (4) inherentphysicalfundamentallaws(eg,thermalandotherelectricnoises,Brownianmotioninmaterials,andradiation)

Ininstrumentationsystems,errorscanbebroadlyclassifiedassystematic,random,orgrosserrorsForfurtherinformation,readerscanrefertoChapters2and4

Measurements, Instrumentation, and Sensors

1.3.5 Error reduction

ControllingerrorsisanessentialpartofmeasurementsandinstrumentationVarioustechniquesareavailabletoachievethisobjectiveTheerrorcontrolbeginsinthedesignstagesbychoosingtheappro-priatecomponents,filtering,andbandwidthselection;byreducingthenoise;andbyeliminatingtheerrorsgeneratedbytheindividualsubunitsofthecompletesystemInagooddesign,theerrorsofthepreviousgroupmaybecompensatedadequatelybythefollowinggroups

TheaccuracyofinstrumentscanbeincreasedbypostmeasurementcorrectionsVariouscalibrationmethodsmaybeemployedtoalterparametersslightlytogivecorrectresultsInmanycases,calibrationgraphs,mathematicalequations,tables,theexperiencesoftheoperators,andthelikeareusedtoreducemeasurementerrorsInrecentyears,withtheapplicationofdigitaltechniquesandintelligentinstru-ments, error corrections are made automatically by thecomputers or the devices themselvesMoreinformationisavailableinChapters8and9

Inmanyinstrumentationsystems,theapplicationofcompensationstrategyisusedtoincreasestaticanddynamicperformancesInthecaseofstaticcharacteristics,compensationscanbemadebymanymethods,includingintroducingopposingnonlinearelementsintothesystem,usingisolationandzeroenvironmen-talsensitivity,opposingcompensatingenvironmentalinputs,usingdifferentialsystems,andemployingfeedbacksystemsOntheotherhand,dynamiccompensationcanbeachievedbyapplyingthesetech-niquesaswellasbyreducingharmonics,usingfilters,adjustingbandwidth,usingfeedbackcompensationtechniques,andthelikeFurtherinformationondynamicerrormeasurementscanbefoundinChapter12

1.3.6 Calibration of Instruments

ThecalibrationofallinstrumentsisessentialforcheckingtheirperformancesagainstknownstandardsThisprovidesconsistencyinreadingsandreduceserrors,thusvalidatingthemeasurementsuniversallyAfteraninstrumentiscalibrated,futureoperationisdeemedtobeerrorboundforagivenperiodoftimeforsimilaroperationalconditionsThecalibrationprocedureinvolvescomparisonoftheinstru-mentagainstprimaryorsecondarystandardsInsomecases,itmaybesufficienttocalibrateadeviceagainstanotheronewithaknownaccuracy

Many nations andorganizations maintainlaboratories withtheprimary functions ofcalibratinginstrumentsandfieldmeasuringsystemsthatareusedineverydayoperationsExamplesoftheselabo-ratoriesareNationalAssociationofTestingAuthorities(NATA)ofAustraliaandtheBritishCalibrationServices(BCS)DetailedinformationoncalibrationisavailableinChapter8

CalibrationsmaybemadeunderstaticordynamicconditionsAtypicalcalibrationprocedureofacomplexprocessinvolvingmanyinstrumentsisillustratedinFigure12Inanidealsituation,for

Element or system under calibration

Parameter 1 Standard instrument 1 Standard instrument 2Parameter 2 Standard instrument n Parameter n

Output 1 Standard instrument 1

Calibrated instrument 1

Output 2 Standard instrument 2 Calibrated instrument 2

Output k Standard instrument k Calibrated instrument k

FIGURE.1.2 InstrumentsneedtobefrequentlycalibratedsequentiallyforallaffectinginputsCalibrationsare

madeunderstaticordynamicconditionsbyvaryingasingleinputandobservingthecorrespondingoutputwhile keepingalltheotherinputsconstantuntilallinputsarecovered

1-6 Instrumentation and Measurement Concepts

aninstrumentthatresponsetoamultitudeofphysicalvariables,acommonlyemployedmethodisbykeepingalltheinputsconstantexceptoneTheinputisvariedinincrementsinincreasinganddecreasingdirectionsoveraspecifiedrangeTheobservedoutputthenbecomesafunctionofthatsingleinputThecalibrationiscontinuedinasimilarmanneruntilallotherinputsarecoveredForbetterresults,thisproceduremayberepeatedbyvaryingthesequencesofinputs,thusdevel-opingafamilyofrelationshipsbetweentheinputsandtheoutputsAsaresultofthesecalibrationreadings,theinputandoutputrelationusuallydemonstratesstatisticalcharacteristicsFromthesecharacteristics,appropriatecalibrationcurvescanbeobtained,andotherstatisticaltechniquescanbeapplied

1.4 analog and Digital Instruments

InstrumentscanbeanalogordigitaloracombinationofthetwoNowadays,mostinstrumentsareproducedtobedigitalbecauseoftheadvantagestheyofferHowever,thefrontendofmajorityofinstrumentsisstillanalog;thatis,mostofthesensorsandtransducersgenerateanalogsignalsThesignalsinitiallyareconditionedbyanalogcircuitsbeforeconvertingintodigitalformforfurthersig-nalprocessingItisimportanttomentionthatnowadays,digitalinstrumentsoperatingpurelyondigitalprinciplesarebeingdevelopedForinstance,today’ssmartsensorscontainthecompletesignalconditioncircuitsinasinglechipintegratedwiththesensoritselfTheoutputofsmartsensorscanbeinterfaceddirectlywithotherdigitaldevicesMoreinformationonsmartsensorscanbefoundinChapter9

1.4.1 analog Instruments

mits,displays,andstoresdatainanalogformThesignalconditioningisusuallymadebyintegratingmanyfunctionalblockssuchasbridges,amplifiers,filters,oscillators,modulators,offsetsandlevelcon-verters,andbuffers,asillustratedinFigure13Generally,intheinitialstages,thesignalsproducedbythesensorsandtransducersareconditionedmainlybyanalogelectronics,eveniftheyareconfiguredasdigitalinstrumentslater

AnaloginstrumentsarecharacterizedbycontinuoussignalsApurelyanalogsystemmeasures,trans-Inanaloginstruments,thechangesinamplitudes,phases,orfrequenciesoracombinationofthethreeconveytheusefulinformationinresponsetophysicalvariablesThesesignalscanbedeterministicornondeterministicAsinthecasewithallsignal-bearingsystems,thereareusefulsignalsthatrespondtothephysicalphenomenaandunwantedsignalresultingfromvariousformsofnoiserequiringexten-

sivefilteringandothersignalprocessingasexplainedinthechaptersinElectrical,.Optical,.Chemical, and.Biomedical.Measurement

minedIfthesignalvariesinaprobabilisticmanner,itsfuturecanbedeterminedonlybystatisticalmethodsThemathematicalandpracticaltreatmentofanaloganddigitalsignals,havingforeseen,sto-chastic,andnondeterministicproperties,isaverylengthysubject,andavastbodyofinformationcanbefoundintheliterature;therefore,theywillnotbetreatedhere

Analogsignalscanalsobenondeterministic;thatis,thefuturestateofthesignalcannotbedeter-Sensor and/or transducer

Output display

Physical

variable circuitInput amplifierPre- Filters andamplifiers Transmission

FIGURE.1.3

Analoginstrumentsmeasure,transmit,display,andstoredatainanalogformThesignalcondition-inginvolvessuchcomponentsasbridges,amplifiers,filters,oscillators,modulators,offsetsandlevelconverters, buffers,andsoon

Measurements, Instrumentation, and Sensors

1.4.2 Digital Instruments

Inmoderninstruments,theoriginaldataacquiredfromthephysicalvariablesareusuallyinanalogformThisanalogsignalisconvertedtodigitalbeforebeingpassedontotheotherpartsofthesystemForconver-sionpurposes,analog-to-digital(A/D)convertersareusedtogetherwithappropriatesample-and-holdandmultiplexingdevicesThetypicalcomponentsofadigitalinstrumentareillustratedinFigure14ThedigitalsystemsareparticularlyusefulinperformingmathematicaloperationsandstoringandtransmittingdataA/Dconversioninvolvesthreestages:sampling,quantization,andencodingTheNyquistsamplingtheoremmustbeobservedduringsampling;thatis,“thenumberofsamplespersecondmustbeatleasttwicethehighestfrequencypresentinthecontinuoussignal”Asaruleofthumb,dependingonthesignificanceofthehighfrequencies,thesamplingmustbeabout5to10timesthehighestfrequencyofthesignalThenextstageisthequantization,whichdeterminestheresolutionofthesampledsignalsThe quantizationerrordecreasesasthenumberofbitsincreasesIntheencodingstage,thequantizedvaluesareconvertedtobinarynumberstobeprocesseddigitallyOnceindigitalform,thedatacanfurtherbeprocessedbyemployingvarioustechniquessuchasFFTanalysis,digitalfiltering,sequentialorlogicaldecisionmaking,correlationmethods,spectrumanalysis,andmore

1.5 Sensors and transducers

AsensorisadevicethatrespondstoachangingphenomenonAtransducerisadevicethattransfersenergyfromoneformtoanother

Sensorsandtransducerscanbecategorizedinanumberofwaysdependingonfactorssuchas theenergyinputandoutput,inputvariables,sensingelements,andelectricorphysicalprinciplesFromthe energyinputandoutputpointofview,therearethreetypes:themodifiers,theself-generators,andthemodulators

Inmodifiers,aparticularformofenergyismodifiedratherthanconverted;therefore,thesameformofenergyexistsinboththeinputandtheoutputstagesInself-generators,electricsignalsareproducedfromnonelectricinputswithouttheapplicationofexternalenergyTypicalexamplesarepiezoelectrictransducersandphotovoltaiccellsModulators,ontheotherhand,produceelectricoutputsfromnon-electricinputs,buttheyrequireanexternalsourceofenergyStraingagesaretypicalexamplesofsuchdevicesSomeexamplesofsensorsandmeasurementsarelistedasfollows:

Analog signal conditioner Multiplexer

D/A converter

FIGURE.1.4 Digitalinstrumentshavemoresignal-processingcomponentsthananalogcounterpartsHowever,

theyhavetheadvantageofdatahandling,storing,displaying,andtransmitting

1-8 Instrumentation and Measurement Concepts

• Time and frequency, discussed in Part IV of Electrical, Optical, Chemical, and Biomedical Measurement

ThepresenttrendinsensortechnologyhasbeenshiftedtowardICsensorsintheformofmicrosys-ICdevicesrefertothedimensionsofdevicesinmicrometer(10−6m)ranges,whereasnanotechnologyreferstothedimensionsofdevicesinnanometer(10−9m)rangesThemicrosystemstechnology(MST)

tems(MEMS)AnothersubsetofMSTisthemicroelectro-optical.systems(MEOMs)andsystems-on-chip

iswellestablishedandsimplyknownastheMSTAsubsetofMSTisthemicroelectromechanical.sys-sionsintheorderoffewmicrometers

(SOC)devicesMostofthesensorsmanufacturedbyMEMsandMEOMsare3Ddeviceswithdimen-sivelyfortemperature,pressure,andradiationmeasurements,aswellasmechanical,chemical,envi-ronmental, biomedical, biological variables, and implantable sensors, and many others A  typicalexampleisillustratedinFigure15,anddetailedinformationonsuchdevicescanbefoundinPart Iof

Forexample,single-chipmicrosensorsandmicroinstrumentsarebeingdevelopedandusedexten-Electrical,.Optical,.Chemical,.and.Biomedical.MeasurementThisparticularsingle-chipimplementation

of microinstrumentation system is based on complementary metal–oxide–semiconductors (CMOS)andothertechnologiesItincorporatesvoltage,current,andcapacitive-sensorinterface;atemperaturesensor;a10-channel12bitA/Dconverter;andan8bitmicrocontrollerwitha 16bithardwaremultiplieranda40bitaccumulatorThisdeviceoperateson3Vpowersupplydrawing16mAwhenfullypoweredor850μAatstandby

Capacitive sensor interface

Filters 12 bitA/D

FIGURE.1.5 Blockdiagramofatypicalmicro-instrument

Measurements, Instrumentation, and Sensors

conductorsandtheirassociatedtechnologiesInthemanufacturingprocess,theuseofothermaterialsandthedepositionofthickandthinfilmsareoftenrequiredtogivethesensingmaterialsusefulproper-tiesotherwisetheywouldnothaveForexample,piezoelectricmaterialfilmsappliedtosiliconwafersprovidepiezoelectricpropertiesThereareseveralmethodsofdepositingthinandthickfilmsonsub-stratesorsemiconductorwafersSomeofthemethodsarespincasting,vacuumdeposition,sputtering,electroplating,screenprinting,etc

Modernmicrosensorsandmicroinstrumentsarefabricatedbymakingfulluseofpropertiesofsemi-1.5.1 Smart Sensors

etersintoelectricsignalsTheyrequireextensiveexternalcircuitsandcomponentsforsignalprocessing

Aconventionalsensormeasuresphysical,biological,orchemicalparametersandconvertstheseparam-

anddisplayThetermsmart.sensorwasadoptedinthemid-1980stodifferentiateanewclassofsen-sorsfromtheconventionalonesSmartsensorshaveintelligenceofsomeformandcanconvertarawsensorsignalintoalevelthatmakesthemmuchmoreconvenienttouseTheyprovidevalue-addedfunctions,thusincreasingthequalityofinformationratherthanjustpassingtherawsignalTheycanperformfunctionssuchasself-identification,self-testing,lookuptables,calibrationcurvesaswellasabilitytocommunicatewithotherdevicesThesefunctionsareconductedbytheintegrationofsensorswithmicrocontrollersormicroprocessororlogiccircuitsinthesamechipUnderstandably,themicro-processorcontainsRAMandROMandcanconvenientlybeprogrammedexternallySmartsensorsalsoincludesignalamplification,conditioning,processing,andA/Dconversions

niquesprogrammedandheldonboardthechipThesesensorsarecapableofassimilatingalargequan-tityofdata;hence,theyarecapableoftakingautonomousandappropriateactionstoachievegoalsinanydynamicallychangingenvironmentTheyareadaptableinanticipatingeventsandcomplexitiesoftheprocess;therefore,sensing,learning,andself-configurationsarethekeyelementsIntelligentsen-sorsappearinthemarketplaceaspressuresensorsandaccelerometers,biosensors,chemicalsensors,opticalsensors,magneticsensors,andsoonIntelligentvisionsystemsandparallelprocessors–basedsensorsaretypicalexamplesofsuchdevices

Avarietyofsmartsensorsaremanufacturedwiththeneuralnetworkandotherintelligencetech-1.5.2 Wireless and autonomous Sensors and Instruments

Sudden growth in the wireless communication technology has prompted the expansion of wirelessindustrybyorderofmagnitudesThisislargelysupportedbyimprovementindigitalandRFcircuitfab-ricationmethods,advancesinsignal-processingtheoryandapplications,andemergenceofnewlarge-scalewireless-relatedICsandothersupportingdevicesParticularly,thenewICtechnologymakesradioequipmentsmaller,cheaper,andmorereliableInparalleltoindustrialexpansion,consumeracceptanceandneedforproductspermitwidespreaddeploymentofthewirelesscommunicationsystemsTrendswillcontinueatanevengreaterpaceinthecomingyears

WirelesstechnologyisusedextensivelyinmodernsensorsandinstrumentationAtypicalwirelesssensorcontainssensingelements,signal-processingcircuits,andwirelesscommunicationcomponentsinthesamechipSeveralminiaturizationtechniquesareavailableforwirelesssensors,includingSOC,MEMS,andASICsInawirelesssensor,therearefivemaincomponentsthatneedtobeintegratedforacompletesystem;thesecomponentsaresensor,signal-processingcircuitry,radio,battery,andpackageRadio,sensors,andsignal-processingcircuitrycanbereducedinsizethroughhybridcircuits,MEMS,ormixed-signalASICdesignHowever,thepowersupplycomponentsmustbedealtwithseparatelyas

explainedinChapter90ofthisbookandChapter13ofElectrical,.Optical,.Chemical,.and.Biomedical Measurement

bledigitalhardware,memoryandstorage,input/outputandcommunicationcomponents,andothers,for

Wirelessinstrumentsconsistoffivemaincomponents—sensorsandsignalconditioners,programma-1-10 Instrumentation and Measurement Concepts

example,displays,keypads,andpowersuppliesAtypicalwirelessinstrumentisillustratedinFigure16Instrumentsdifferfromeachotherbythewaythattheyhandle,transmit,anddisplayinformationFurtherinformationcanbefoundinPartIX,whichisdedicatedtowirelesstechnologyforinstrumentsandsensorsAutonomoussensorsareself-poweredmeasurementdevicesthatarecapableofcommunicatingwire-lessly They serve as the nodes in distributed data acquisitionsystems and wireless sensor networks(WSN)findingapplicationssuchasinhealthcare,aerospace,andenvironmentalmonitoringToincreasetheirautonomy,autonomoussensorsseektoreducetheiraveragepowerconsumptionbyworkinginlow

powermodeswheneverpossibleTheyspendmostofthetimeinsleep(standby)modeandonlywake up

toperformspecificactions—namely,measurement,processing,andtransmission/receptionofdataAutonomous sensors are composed of sensors, signal conditioners, processors, and transceiversSensorsconvertasignalfromaphysicalorchemicalquantitytoacorrespondingsignalintheelectricdomainOften,commercialtransceiversareusedforwirelesscommunicationTheytransmitinthefree-licensedISMbandsandcanuseaproprietaryorstandard(eg,IEEE802154)protocolFurtherinformationonautonomoussensorscanbefoundinChapter90

1.6 Instrumentation and Networks

Networkingofhardwareandsoftwareresourcesisessentialtobringmultiplesensorsandinstrumentstogetherforexchangeofinformation,collaborativeoperations,andsharingoffunctionsofequipmentanddevicesNetworksaremadebythecollectionofdevices,themediumthatlinksthesedevices,and

thesoftwarethatsupportsthenetworkingoftheentiresystemAsystemismadefromagroupofinter-relatedpartswiththefocusofestablishinganinterrelationshipbetweenthemtoimproveefficiency,tofacilitateintegrationoftheapplication,andtosharetheresources

worked Many processes require measurements of hundreds and perhaps thousands of parametersemployingmanyinstrumentsTheresultingarrangementforperformingtheoverallmeasurementin

Duetorecentprogressincommunicationstechnology,sensorsandinstrumentscaneasilybenet-acomplexprocessesiscalledthemeasurement.systemInmeasurementsystems,instrumentsoperate

municatedbetweentheinstrumentsthemselvesandthecontrollersorbetweeninstrumentsandotherdigitaldevicessuchasrecorders,displayunits,printers,routers,basestations,orhostcomputerConnectingdevicestogethertoformnetworksisnotanewconcept,andithasbeenoperationalformanyyearsinadiverserangeofapplicationsIntheearliernetworks,almostallthecommunicatingdeviceswereconnectedbywires;hence,theywerelargelyfixedinspaceThedevicesinmodernnetworks,asdiscussedinthisbook,canbeconfiguredbyusingwirelesscommunicationtechnologyandrelatedsoftware;hence,theycanhavemobilityinspacewhilestillmaintainingfeasiblenetworksTherefore,

autonomouslybutinacoordinatedmannerInformationgeneratedbyeachinstrumentmaybecom-modernnetworkscanbeviewedas(1)wired.networksinwhichthecommunicationdevicesareconnected bywires,hencelargelyfixedinspace,(2)wireless.networksinwhichdevicescommunicatewirelessly,

Sensors and transducers

Physical

variables

Transmission and/or display

Microprocessor and software

Multiplexers and A/D converters

RF transceiver

RF transceiver

Computer or microprocessor system

FIGURE.1.6 Componentsofawirelessinstrument

Measurements, Instrumentation, and Sensors

hencecanmoveinspace,and(3)hybrid.networksinwhichbothwiredandwirelesstechniquesare

usedincombinationAtthemoment,mobilenetworksbasedonwirelesstechniquesprovideprimarilyvoice-basedservices,buttheyareincreasinglyhandlingdataandotherformsofinformationWirelessnetworkscanmatchsimilarfunctionsasfixednetworksplustheyoffermanyadvantagessuchasthereductionincostforinitialsetupandmaintenance

DevicesneednetworksoftwaretoissuetherequestsandresponsesthatallowthemcommunicatewitheachothersuccessfullyAcommunicationprocessbetweentwodevicesisillustratedinFigure17Inthiscase,communicationistakingplaceinsimplexform;deviceAissendinginformationtodeviceB

ing.systems(NOSs)NOSscontroltheaccesstonetworkrecoursesExamplesofcommonNOSsusedin

Inmanynetworks,communicatingdevicesinvokealayerofcodes,whichiscallednetwork.operat-computersareWindowsNET,WindowsXP,Novell’sNetWare,etc

MostnetworksoftwarepackagescomewithmodulesforloggingonandoffthenetworkLoggingonandloggingoffnetworkmodulesmayincludeconsiderationssuchaspasswordsecurity,validationofuseraccesstospecificfilesandsoftware,automaticlog-onfeatureforsomedevices,helpmenus,anderrormessagesMore information on instrument networks can be found in Part IX of this book and Part I of

Electrical,.Optical,.Chemical,.and.Biomedical.Measurement

1.7 Software Support for Sensors and Instruments

Thesoftwareisatermfordescribingtheroleofprograms,procedures,anddocumentationinprogram-tionsystemItcanbedividedintothreemajorgroups:(1)systemsoftware,(2)programmingsoftware,and(3)applicationsoftwareAllaredevelopedusingprogramminglanguages,scriptinglanguages,machinelanguagesorassemblycodes,orFPGAconfigurationsSomeexamplesofprogramminglanguagesareCorC++,Java,andBasic