【英文标准名称】:StandardPracticeforDeterminingContrastSensitivityinRadioscopy
【原文标准名称】:射线检查法中对比灵敏度测定的标准实施规范
【标准号】:ASTME1647-2003
【标准状态】:现行
【国别】:
【发布日期】:2003
【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】:(Practice)
【标准水平】:()
【中文主题词】:图像质量;图像质量指示器;直线;γ辐射;射线检查;放射性照射;辐照;试验
【英文主题词】:contrastsensitivitygage;gammaray;imageformation;imageprocessing;imagequalityindicator;line-pairspermillimeter;penetratingradiation;spatialresolution;X-ray
【摘要】:Thecontrastsensitivitygagemeasurescontrastsensitivityindependentoftheimagingsystemspatialresolutionlimitations.Thethicknessrecessdimensionsofthecontrastsensitivitygagearelargewithrespecttothespatialresolutionlimitationsofmostimagingsystems.Fourlevelsofcontrastsensitivityaremeasured:4%,3%,2%,and1%.Thecontrastsensitivitygageisintendedforuseinconjunctionwithahigh-contrastresolutionmeasuringgage,suchastheEN462x2013;5DuplexWireImageQualityIndicator.Suchgagesmeasurespatialresolutionessentiallyindependentoftheimagingsystem’contrastsensitivity.Suchmeasurementsareappropriateforthequalificationandperformancemonitoringofradiographicandradioscopicimagingsystems.Radioscopic/radiographicsystemperformancemaybespecifiedbycombiningthemeasuredcontrastsensitivityexpressedasapercentagewiththespatialresolutionexpressedinmillimetersofunsharpness.FortheEN462x2013;5spatialresolutiongage,theunsharpnessisequaltotwicethewirediameter.Forthelinepairgage,theunsharpnessisequaltothereciprocaloftheline-pair/mmvalue.Asanexample,animagingsystemthatexhibits2%contrastsensitivityandimagesthe0.1mmEN462x2013;5pairedwires(equivalenttoimaging5line-pairs/millimeterresolutiononaline-pairgage)performsata2%x2013;0.2mmsensitivitylevel.AstandardmethodofevaluatingoverallradioscopicsystemperformanceisgiveninPracticeE1411andinEN13068x2013;1.1.1Thispracticecoversthedesignandmaterialselectionofacontrastsensitivitymeasuringgageusedtodeterminetheminimumchangeinmaterialthicknessordensitythatmaybeimagedwithoutregardtospatialresolutionlimitations.1.2Thispracticeisapplicabletotransmitted-beamradiographicandradioscopicimagingsystemsutilizingX-rayandgammarayradiationsources.1.3Thevaluesstatedininch-poundunitsaretoberegardedasstandard.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.Forspecificsafetystatements,seeNIST/ANSIHandbook114Section8,CodeofFederalRegulations21CFR1020.40and29CFR1910.96.
【中国标准分类号】:C43
【国际标准分类号】:
【页数】:5P.;A4
【正文语种】:

标准名称：	出口种用虾检验检疫规程
英文名称：	Protocol of inspection and quarantine for exported breeding shrimp
中标分类：	农业、林业 >> 水产、渔业 >> 水产、渔业综合
ICS分类：	食品技术 >> 肉、肉制品和其他动物类食品 >> 鱼和水产品
发布部门：	中华人民共和国国家质量监督检验检疫总局
发布日期：	2005-02-17
实施日期：	2005-07-01
首发日期：
作废日期：
起草单位：	国家认证认可监督管理委员会
出版社：	中国标准出版社
出版日期：	2005-05-01
页数：	6页
书号：	155066·2-16184

本标准规定了出口种用虾检验检疫规程。本标准适用于出口种用虾的检验检疫。

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