【英文标准名称】:StandardGuideforComputedTomography(CT)Imaging
【原文标准名称】:计算机断层摄影(CT)成像的标准指南
【标准号】:ASTME1441-2000(2005)
【标准状态】:现行
【国别】:
【发布日期】:2000
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E07.01
【标准类型】:(Guide)
【标准水平】:()
【中文主题词】:计算机断层摄影;导则;图例;信息处理
【英文主题词】:computedtomography(CT);contrast;contrast-detail-dose(CDD);detectability;imaging;modulationtransferfunction(MTF);nondestructiveevaluation(NDE);pointspreadfunction(PSF);reconstruction;resolution;scan;X-rayattenuation
【摘要】:1.1Computedtomography(CT)isaradiographicmethodthatprovidesanidealexaminationtechniquewhenevertheprimarygoalistolocateandsizeplanarandvolumetricdetailinthreedimensions.BecauseoftherelativelygoodpenetrabilityofX-rays,aswellasthesensitivityofabsorptioncrosssectionstoatomicchemistry,CTpermitsthenondestructivephysicaland,toalimitedextent,chemicalcharacterizationoftheinternalstructureofmaterials.Also,sincethemethodisX-raybased,itappliesequallywelltometallicandnon-metallicspecimens,solidandfibrousmaterials,andsmoothandirregularlysurfacedobjects.Whenusedinconjunctionwithothernondestructiveevaluation(NDE)methods,suchasultrasound,CTdatacanprovideevaluationsofmaterialintegritythatcannotcurrentlybeprovidednondestructivelybyanyothermeans.1.2ThisguideisintendedtosatisfytwogeneralneedsforusersofindustrialCTequipment:(1)theneedforatutorialguideaddressingthegeneralprinciplesofX-rayCTastheyapplytoindustrialimaging;and(2)theneedforaconsistentsetofCTperformanceparameterdefinitions,includinghowtheseperformanceparametersrelatetoCTsystemspecifications.Potentialusersandbuyers,aswellasexperiencedCTinspectors,willfindthisguideausefulsourceofinformationfordeterminingthesuitabilityofCTforparticularexaminationproblems,forpredictingCTsystemperformanceinnewsituations,andfordevelopingandprescribingnewscanprocedures.1.3ThisguidedoesnotspecifytestobjectsandtestproceduresforcomparingtherelativeperformanceofdifferentCTsystems;nordoesittreatCTinspectiontechniques,suchasthebestselectionofscanparameters,thepreferredimplementationofscanprocedures,theanalysisofimagedatatoextractdensitometricinformation,ortheestablishmentofaccept/rejectcriteriaforanewobject.1.4Standardpracticesandmethodsarenotwithinthepurviewofthisguide.Thereaderisadvised,however,thatexaminationpracticesaregenerallypartandapplicationspecific,andindustrialCTusageisnewenoughthatinmanyinstancesaconsensushasnotyetemerged.ThesituationiscomplicatedfurtherbythefactthatCTsystemhardwareandperformancecapabilitiesarestillundergoingsignificantevolutionandimprovement.Consequently,anattempttoaddressgenericexaminationproceduresiseschewedinfavorofprovidingathoroughtreatmentoftheprinciplesbywhichexaminationmethodscanbedevelopedorexistingonesrevised.1.5TheprincipaladvantageofCTisthatitnondestructivelyprovidesquantitativedensitometric(thatis,densityandgeometry)imagesofthincrosssectionsthroughanobject.Becauseoftheabsenceofstructuralnoisefromdetailoutsidethethinplaneofinspection,imagesaremucheasiertointerpretthanconventionalradiographicdata.Thenewusercanlearnquickly(oftenuponfirstexposuretothetechnology)toreadCTdatabecausetheimagescorrespondmorecloselytothewaythehumanmindvisualizesthree-dimensionalstructuresthanconventionalprojectionradiography.Further,becauseCTimagesaredigital,theymaybeenhanced,analyzed,compressed,archived,inputasdataintoperformancecalculations,comparedwithdigitaldatafromotherNDEmodalities,ortransmittedtootherlocationsforremoteviewing.Additionally,CTimagesexhibitenhancedcontrastdiscriminationovercompactareaslargerthan20to25pixels.Thiscapabilityhasnoclassicalanalog.Contrastdiscriminationofbetterthan0.1%atthree-sigmaconfidencelevelsoverareasassmallasone-fifthofonepercentthesizeoftheobjectofinterestarecommon.1.6Withpropercalibration,dimensionalinspectionsandabsolutedensitydeterminationscanalsobemadeveryaccurately.Dimensionally,virtuallyallCTsystemsprovideapixelresolutionofrough......
【中国标准分类号】:L81;C43
【国际标准分类号】:35_240_80
【页数】:33P.;A4
【正文语种】:
基本信息
| 标准名称： | 锰矿石砷含量的测定二乙氨基二硫代甲酸银分光光度法 |
| 英文名称： | Manganese ores - Determination of arsenic content - Silver diethyldithiocarbamate spectrophotometric method |
| 中标分类： |
矿业 >>
黑色金属矿 >>
锰矿 |
| ICS分类： |
采矿和矿产品 >>
金属矿 >>
锰矿
|
| 替代情况： | 替代GB/T 1516-1979 |
| 发布部门： | 中华人民共和国国家质量监督检验检疫总局 中国国家标准化管理委员会 |
| 发布日期： | 2006-09-12 |
| 实施日期： | 2007-02-01 |
| 首发日期： | 1979-02-28 |
| 作废日期： | |
| 主管部门： | 中国钢铁工业协会 |
| 提出单位： | 中国钢铁工业协会 |
| 归口单位： | 全国钢标准化技术委员会 |
| 起草单位： | 桂林矿产地质研究院 |
| 起草人： | 靳晓珠、杨仲平、李赋屏、黄华鸾、施意华 |
| 出版社： | 中国标准出版社 |
| 出版日期： | 2007-02-01 |
| 页数： | 平装16 开/页数：8/字数：8 |
| 计划单号： | 20021424-T-605 |
| 书号： | 155066·1-27698 |
适用范围
本标准规定了用二乙氨基二硫代甲酸银分光光度法测定砷含量的方法
前言
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目录
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引用标准
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所属分类： 矿业 黑色金属矿 锰矿 采矿和矿产品 金属矿 锰矿