measuring system

Function

Ameasurementsystemisacollectionofinstrumentsorgauges,standards,operations,methods,fixtures,software,personnel,environmentandassumptionsusedtoquantitativelymeasureorqualitativelyevaluatethemeasuredcharacteristics;Thewholeprocessusedtoobtainmeasurementresults.

IntheISO/TS16949standard,itprovidesaMeasurementSystemsAnalysis(MeasurementSystemsAnalysis),referredtoasMSA,whichisoneofthefivemanualsofthestandard.

Measurementsystemanalysisalsohasspecialsoftwareforanalysis.

Purpose

·Determinewhetherthedatausedisreliable:

·Evaluatethenewmeasuringinstrument

·ComparethetwodifferentComparisonofmeasurementmethods

·Evaluationofmeasurementmethodsthatmayhaveproblems

·Identifyandsolvethemeasurementsystemerrorproblem

Composition

1)Measuringtool:anydeviceusedtoobtainmeasurementresults.

2)Measuringsystem:

Measurementtool(equipment)

Measurementpersonnel(operator)

Measuredworkpiece(parts)

procedure,methods(procedure,methods)

Interactionoftheabovepoints

Idealsystem

TheidealmeasurementsystemisusedeverytimeItshouldonlyproduce"correct"measurementresults.Eachmeasurementresultshouldalwaysmatchastandardvalue.Ameasurementsystemthatcanproduceidealmeasurementresultsshouldhavethestatisticalcharacteristicsofzerovariance,zerobias,andzeroprobabilityofmisclassificationofanyproductundertest.

Statisticalcharacteristicsthatthemeasurementsystemshouldhave

1.Themeasurementsystemmustbeunderstatisticalcontrol,whichmeansthatthevariationinthemeasurementsystemcanonlybeduetoordinaryreasonsratherthanduetoCausedbyspecialreasons.Thiscanbecalledstatisticalstability.

2.Thevariationofthemeasurementsystemmustbesmallerthanthevariationofthemanufacturingprocess.

3.Thevariationshouldbelessthanthetolerancezone.

4.Themeasurementaccuracyshouldbehigherthanthehigheraccuracyoftheprocessvariationandtolerancezone.Generallyspeaking,themeasurementaccuracyistenofthehigheraccuracyoftheprocessvariationandtolerancezone.Onepart.

5.Thestatisticalcharacteristicsofthemeasurementsystemmayvarywiththechangesofthetesteditems.Ifthisisthecase,themaximumvariationofthemeasurementsystemshouldbelessthanthesmalleroftheprocessvariationandthetolerancezone.

Standardsformeasurementsystemanalysis

1.Nationalstandards;

2.First-levelstandards(connectingnationalstandardsandprivatecompanies,scientificresearchinstitutions,etc.);

3.Thesecondlevelstandard(fromthefirstlevelstandardtothesecondlevelstandard);

4.Theworkingstandard(fromthesecondlevelstandardtotheworkingstandard).

Othersystems

ArcGISmeasurementsystem

SpatialAnalystdoesnotdistinguishfourdifferenttypesofmeasurementvalues​​whenprocessingormanipulatingvalues.Mostmathematicaloperationscanbeperformedonratiovalues,butifyouperformmultiplication,division,orsquarerootoperationsonintervalvalues,ordinalvalues,andnominalvalues,theresultsareusuallymeaningless.Ontheotherhand,itmakessensetoperformsubtraction,addition,andBooleanoperationsonintervalvalues​​andordinalvalues.Attributeprocessingwithinandbetweenrasterdatasetsismostefficientwhenusinganominalmeasurementsystem.

Ratio

Thevalueofaratiomeasurementsystemisexpressedasalinearratioofacertainvaluetoafixedzeropoint.Youcanperformmathematicaloperationsonthesevalues​​togetpredictableandmeaningfulresults.Examplesofratiomeasurementsincludeage,distance,weight,andvolume.

Interval

Time,calendaryear,Fahrenheittemperaturescale,andpHareallexamplesofintervalmeasurements.Thesevalues​​areproportionaltothelinearcalibration,buttheyarenotproportionaltothetruezeropointintimeorspace.Sincethereisnorealzeropoint,althoughrelativecomparisonscanbemadebetweenmeasuredvalues,theexactvalues​​ofratiosandratiosarenotverymeaningful.

Ordinal

Theordinalvaluecandeterminetheposition.Thesemeasurementscanshowlocation(suchasthefirst,second,andthird),buttheydonotestablishmagnitudeorrelativeproportions.Itisnotpossibletoindicatehowgood,bad,beautiful,healthy,orstrongthingsarethroughordinalnumbers.Forexample,thespeedofthefirst-rankedathleteinacompetitionmaynotbetwiceasfastasthesecond-rankedathlete.Identifyingthewinnerbasedonpositionalonecannotknowhowmuchfastertheathleteinthefirstplaceisthantheathleteinthesecondplace.

Nominal

Thevalueassociatedwiththemeasurementsystemisusedtodistinguishinstances.Thesevalues​​canalsoestablishgroups,classes,members,orcategoriesassociatedwiththeobject.Thesevalues​​areindicativeoftraits,notquantitative,sotheyhavenothingtodowithfixedpointsorlinearscales.Codingschemesforlanduse,soiltype,oranyotherattributescanbeusedasnominalmeasurements.Othernominalvalues​​includesocialsecuritynumbers,postalcodes,andtelephonenumbers.