測量恒溫箱|技術好壞的評定
一、評定目的區(qū)別:
測量不確定度為的是表明被測量值的分散性;
測量誤差為的是表明測量結(jié)果偏離真值的程度。
(一)、assessthepurposeofdifference:
uncertaintyofmeasurementinordertoshowthatmeasuredvaluesofdispersion;
measurementerrorinordertoshowtheresultsofmeasurementareusuallydeviatedfromthetruevalue
ofthedegree.
二、評定結(jié)果的區(qū)別:
測量不確定度是無符號的參數(shù),用標準差或標準差的倍數(shù)或置信區(qū)間的半寬表示,由人們根據(jù)實驗、資料、經(jīng)驗等信息進行評定,可以通過a,b兩類評定方法定量確定;測量誤差為有正號或負號的量值,其值為測量結(jié)果減去被測量的真值,由于真值未知,往往不能準確得到,當用約定真值代替真值時,只可得到其估計值。
(二)、toassesstheresultsofthedifferencebetween:
theparametersofthemeasurementuncertaintyisunsigned,usingthestandarddeviationorthestandard
deviationofmultiplesorhalfwidthofconfidenceinterval,cisaid,bythepeople,accordingtothe
experimentdata,experienceandotherinformationtoassess,cana,btwokindsofassessmentmethod
quantitatively;measurementerrorisplusorminusvalue,itsvalueminusthemeasurementresultsfor
thetruevalueismeasured,duetothetruevalueoftheunknown,oftencannotaccuray,whenagreed
withtruevalueinsteadoftruthvalue,onlytheestimatecanbeobtained.
三、影響因素的區(qū)別:
測量不確定度由人們經(jīng)過分析和評定得到,因而與人們對被測量、影響量及測量過程的認識有關;測量誤差是客觀存在的,不受外界因素的影響,不以人的認識程度而改變;
因此,在進行不確定度分析時,應充分考慮各種影響因素,并對不確定度的評定加以驗證。否則由于分析估計不足,可能在測量結(jié)果非常接近真值(即誤差很?。┑那闆r下評定得到的不確定度卻較大,也可能在測量誤差實際上較大的情況下,給出的不確定度卻偏小。
(三)、theinfluencefactorsofthedifferencebetween:
measurementuncertaintybythepeoplethroughanalysisandevaluation,andtobemeasured,therefore
affecttheamountandtheunderstandingofthemeasurementprocessrelated;measurementerroris
objectiveexistence,notinfluencedbyoutsidefactors,notwithpeople'sawarenessandchange;
whenmakingtheuncertaintyanalysis,therefore,shouldfullyconsidervariousinfluencingfactors,
andtheevaluationofuncertaintyofverified.orcausedbyalackofanalysisestimation,
measurementresultsmaybeveryclosetothetruevalue(thatis,theerrorisverysmall)under
theconditionofevaluationofuncertaintyisbigger,alsomayinthecaseofmeasurementerroris
actuallylarger,giventheuncertaintyissmall.
四、按性質(zhì)區(qū)分上的區(qū)別:
測量不確定度不確定度分量評定時一般不必區(qū)分其性質(zhì),若需要區(qū)分時應表述為:“由隨機效應引入的不確定度分量”和“由系統(tǒng)效應引入的不確定度分量”;測量誤差按性質(zhì)可分為隨機誤差和系統(tǒng)誤差兩類,按定義隨機誤差和系統(tǒng)誤差都是無窮多次測量情況下的理想概念。
(四)、accordingtothenaturetodistinguishthedifferencebetween:
whentheuncertaintyofmeasurementuncertaintycomponentsevaluationgenerallydon'thaveto
distinguishbetweenthenature,whenneedtodistinguishbetweenshouldbeexpressedas:the
uncertaintycomponentsintroducedbyrandomeffectsanduncertaintycomponentsintroducedby
systemeffect;measurementerrorinnaturecanbedividedintotwocategories,randomerrorand
systemerror,accordingtothedefinitionofrandomerrorandsystemerroraretheidealconcept
ofinfiniterepeatedmeasurementsituation.
五、對測量結(jié)果修正的區(qū)別:
“不確定度”一詞本身隱含為一種可估計的值,它不是指具體的、確切的誤差值,雖可估計,但卻不能用以修正量值,只可在已修正測量結(jié)果的不確定度中考慮修正不完善而引入的不確定度;而系統(tǒng)誤差的估計值如果已知則可以對測量結(jié)果進行修正,得到已修正的測量結(jié)果。一個量值經(jīng)修正后,可能會更靠近真值,但其不確定度不但不減小,有時反而會更大。這主要還是因為我們不能確切的知道真值為多少,僅能對測量結(jié)果靠近或離開真值的程度進行估計而已。
(五)、correction:thedifferencebetweentheresultofthemeasurement
impliedtermuncertaintyitselfisakindofcanbeestimatedvalue,itisnotspecific,definite
errorvalues,canbeestimated,butnottocorrectvalue,canonlybeusedintheuncertaintyof
measurementresultsisfixedintocorrectionisimperfectandtheintroductionofuncertainty;and
systemerrorestimateifknowncouldbeamended,theresultofthemeasurementisfixedmeasurement
resultsareobtained.arevisedvalue,theymaybemoreclosetothetruevalue,butitsnotonly
reducetheuncertainty,sometimesitwillbebigger.themainorbecausewecannotknowexactlytrue
valueishowmuch,canonlyonthemeasurementresultsclosetoestimateorleavethetruevalueof
thedegree.