欢迎来到标准图书馆! | 帮助中心 Day Day UP!
标准图书馆
首页 标准图书馆 > 资源分类 > PDF文档下载

ASTM E1647-16

  • 资源大小:129.13KB        全文页数:5页
  • 资源格式: PDF        下载权限:游客/注册会员/VIP会员    下载费用:30Gold 【人民币30元】
游客快捷下载 游客一键下载
会员登录下载
下载资源需要30Gold 【人民币30元】Paypal charge shall be login

邮箱/手机号:
您支付成功后,系统会自动为您创建此邮箱/手机号的账号,密码跟您输入的邮箱/手机号一致,以方便您下次登录下载和查看订单。注:支付完成后需要自己下载文件,并不会自动发送文件哦!

支付方式: 微信支付    支付宝   
验证码:   换一换

友情提示
2、本站资源不支持迅雷下载,请使用浏览器直接下载(不支持QQ浏览器)
3、本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰   

ASTM E1647-16

Designation E1647 − 16Standard Practice forDetermining Contrast Sensitivity in Radiology1This standard is issued under the fixed designation E1647; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the design and material selection ofa contrast sensitivity measuring gauge used to determine theminimum change in material thickness or density that may beimaged without regard to unsharpness limitations.1.2 This practice is applicable to transmitted-beam radio-graphic imaging systems film, radioscopy, computedradiography, and digital detector array image detectors utiliz-ing X-ray and gamma ray radiation sources.1.3 The values stated in inch-pound units are to be regardedas standard. The SI units given in parentheses are for informa-tion only.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific safetystatements, see NIST/ANSI Handbook 114 Section 8, Code ofFederal Regulations 21 CFR 1020.40 and 29 CFR 1910.96.2. Referenced Documents2.1 ASTM Standards2B139/B139M Specification for Phosphor Bronze Rod, Bar,and ShapesB150/B150M Specification for Aluminum Bronze Rod, Bar,and ShapesB161 Specification for Nickel Seamless Pipe and TubeB164 Specification for Nickel-Copper Alloy Rod, Bar, andWireB166 Specification for Nickel-Chromium-Iron Alloys UNSN06600, N06601, N06603, N06690, N06693, N06025,N06045, and N06696, Nickel-Chromium-Cobalt-Molybdenum Alloy UNS N06617, and Nickel-Iron-Chromium-Tungsten Alloy UNS N06674 Rod, Bar, andWireE747 Practice for Design, Manufacture and Material Group-ing Classification of Wire Image Quality Indicators IQIUsed for RadiologyE1025 Practice for Design, Manufacture, and MaterialGrouping Classification of Hole-Type Image Quality In-dicators IQI Used for RadiologyE1255 Practice for RadioscopyE1316 Terminology for Nondestructive ExaminationsE1411 Practice for Qualification of Radioscopic SystemsE1734 Practice for Radioscopic Examination of CastingsE1742 Practice for Radiographic ExaminationE2002 Practice for Determining Total Image Unsharpnessand Basic Spatial Resolution in Radiography and Radios-copyE2445 Practice for Performance Evaluation and Long-TermStability of Computed Radiography Systems2.2 Federal Standards321 CFR 1020.40 Safety Requirements for Cabinet X-raySystems29 CFR 1910.96 Ionizing Radiation2.3 NIST/ANSI StandardsNIST/ANSI Handbook 114 General Safety Standard forInstallations Using Non-Medical X-ray and SealedGamma Ray Sources, Energies to 10 MeV42.4 ISO Standard5ISO 19232–5 Duplex Wire Image Quality Indicator2.5 Other StandardsEN 462 – 5 Duplex Wire Image Quality Indicatorwithdrawn, replaced by ISO 19232–56EN 13068–1 Radioscopic Testing-Part 1 Qualitative Mea-surement of Imaging Properties61This practice is under the jurisdiction of ASTM Committee E07 on Nonde-structive Testing and is the direct responsibility of Subcommittee E07.01 onRadiology X and Gamma Method.Current edition approved June 1, 2016. Published July 2016. Originally approvedin 1994. Last previous edition approved in 2009 as E1647 – 09. DOI 10.1520/E1647-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standard’s Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop SDE, Washington, DC 20401, http//www.access.gpo.gov.4Available fromAmerican Society for NondestructiveTesting ASNT, P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http//www.asnt.org.5Available from International Organization for Standardization ISO, ISOCentral Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,Geneva, Switzerland, http//www.iso.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 DefinitionsDefinitions of terms applicable to this testmethod may be found in Terminology E1316.4. Summary of Practice4.1 It is often useful to evaluate the contrast sensitivity of apenetrating radiation imaging system separate and apart fromunsharpness measurements. Conventional image quality indi-cators IQI’s, such as Test Method E747 wire and PracticesE1025 or E1742 plaque IQIs, combine the contrast sensitivityand resolution measurements into an overall performancefigure of merit, other methods such as included in PracticeE2002 do not address contrast specifically. Such figures ofmerit are often not adequate to detect subtle changes inimaging system performance. For example, in a high contrastimage, unsharpness can increase with almost no noticeableeffect upon overall image quality. Similarly, in an applicationin which the imaging system provides a very sharp image,contrast can fade with little noticeable effect upon the overallimage quality. These situations often develop and may gounnoticed until the system performance deteriorates belowacceptable image quality limits.5. Significance and Use5.1 The contrast sensitivity gauge measures contrast sensi-tivity independent of the imaging system spatial resolutionlimitations. The thickness recess dimensions of the contrastsensitivity gauge are large with respect to the unsharpnesslimitations of most imaging systems. Four levels of contrastsensitivity are measured 4 , 3 , 2 , and 1 .5.2 The contrast sensitivity gauge is intended for use inconjunction with a high-contrast resolution measuring gauge,such as Practice E2002, ISO 19232 – 5 Duplex Wire ImageQuality Indicator7, or a line-pair gauge. Such gauges measuresystem unsharpness essentially independent of the imagingsystem’s contrast sensitivity. Such measurements are appropri-ate for the qualification and performance monitoring of radio-graphic and radioscopic imaging systems with film, realtimedevices, Computed Radiography CR and Digital DetectorArrays DDA.5.3 Radioscopic/radiographic system performance may bespecified by combining the measured contrast sensitivity ex-pressed as a percentage with the unsharpness expressed inmillimetres of unsharpness. For the duplex wire image qualityindicator, the unsharpness is equal to twice the wire diameter.For the line pair gauge, the unsharpness is equal to thereciprocal of the line-pair/mm value. As an example, animaging system that exhibits 2 contrast sensitivity andimages the 0.1 mm paired wires of the duplex wire IQIequivalent to imaging 5 line-pairs/millimeter resolution on aline-pair gauge performs at a 2 –0.2 mm sensitivity level. Astandard method of evaluating overall radioscopic systemperformance is given in Practice E1411 and in EN 13068–1. Aconversion table from duplex wire read out to lp/mm can befound in Practice E2002. For CR system performanceevaluation, this contrast sensitivity gauge is used in PracticeE2445.6. Contrast Sensitivity Gauge Construction and MaterialSelection6.1 Contrast sensitivity gauges shall be fabricated in accor-dance with Fig. 1, using the dimensions given in Table 1, Table2, and Table 3.6.2 The gauge shall preferably be fabricated from theexamination object material. Otherwise, the following materialselection guidelines are to be used6.2.1 Materials are designated in eight groupings, in accor-dance with their penetrating radiation absorption characteris-tics groups 03, 02, and 01 for light metals and groups 1through 5 for heavy metals.6.2.2 The light metal groups, magnesium Mg, aluminumAl, and titanium Ti, are identified as 03, 02, and 01,respectively, for their predominant constituent. The materialsare listed in order of increasing radiation absorption.6.2.3 The heavy metals group, steel, copper base, nickelbase, and other alloys, are identified as 1 through 5. Thematerials increase in radiation absorption with increasingnumerical designation.6.2.4 Common trade names or alloy designations have beenused for clarification of pertinent materials.6.3 The materials from which the contrast sensitivity gaugeis to be made is designated by group number. The gauge isapplicable to all materials in that group. Material groupings areas follows6.3.1 Materials Group 036.3.1.1 The gauge shall be made of magnesium or a mag-nesium alloy, provided it is no more radio-opaque thanunalloyed magnesium, as determined by the method outlined in6.4.6.3.1.2 Use for all alloys where magnesium is the predomi-nant alloying constituent.6.3.2 Materials Group 026.3.2.1 The gauge shall be made of aluminum or an alumi-num alloy, provided it is no more radio-opaque than unalloyedaluminum, as determined by the method outlined in 6.4.7The former version of the duplex wire gauge with the mark EN-462 may alsobe used. FIG. 1 General Layout of the Contrast Sensitivity GaugeE1647 − 1626.3.2.2 Use for all alloys where aluminum is the predomi-nant alloying constituent.6.3.3 Materials Group 016.3.3.1 The gauge shall be made of titanium or a titaniumalloy, provided it is no more radio-opaque than unalloyedtitanium, as determined by the method outlined in 6.4.6.3.3.2 Use for all alloys where titanium is the predominantalloying constituent.6.3.4 Materials Group 16.3.4.1 The gauge shall be made of carbon steel or Type 300series stainless steel.6.3.4.2 Use for all carbon steel, low-alloy steels, stainlesssteels, and magnesium-nickel-aluminum bronze Superston8.6.3.5 Materials Group 26.3.5.1 The gauge shall be made of aluminum bronze AlloyNo. 623 of Specification B150/B150M or equivalent ornickel-aluminum bronze Alloy No. 630 of Specification B150/B150M or equivalent.6.3.5.2 Use for all aluminum bronzes and all nickel alumi-num bronzes.6.3.6 Materials Group 36.3.6.1 The gauge shall be made of nickel-chromium-ironalloy UNS No. N06600 Inconel9. See Specification B166.6.3.6.2 Use for nickel-chromium-iron alloy and 18 nickel-maraging steel.6.3.7 Materials Group 46.3.7.1 The gauge shall be made of 70 to 30 nickel-copperalloy Monel10 Class A or B of Specification B164orequivalent, or 70 to 30 copper-nickel alloy, Alloy G ofSpecification B161 or equivalent.6.3.7.2 Use for nickel, copper, all nickel-copper series orcopper-nickel series of alloys and all brasses copper-zincalloys and all leaded brasses.6.3.8 Materials Group 56.3.8.1 The gauge shall be made of tin-bronze Alloy D ofSpecification B139/B139M.6.3.8.2 Use for tin bronzes including gun-metal and valvebronze and leaded-tin bronzes.6.4 Where the material to be examined is a composite,ceramic, or other non-metallic material, or for some reasoncannot be obtained to fabricate a gauge, an equivalent materialmay be utilized, provided it is no more radio-opaque than theexamination object under comparable penetrating radiationenergy conditions. To determine the suitability of a substitutematerial, radiographs or digital images of identical thicknessesof both materials shall be evaluated. Using film, both materialshall be on one film using the lowest penetrating radiationenergy to be used in the actual examination. Transmissiondensitometer readings for both materials shall be in the rangefrom 2.0 to 4.0. If the optical density of the substitute materialis within 15 to 0 of the examination material, thesubstitute material is acceptable. When using a non-filmtechnique Radioscopy, CR, or DDA, both materials shall bein the same image using the lowest penetrating radiationenergy to be used in the actual examination. The gray valuesshall be in the range of 20 to 60 of saturation gray levelpositive image with higher gray values for less materialthickness. If the gray value of the substitute material is within 15 to 0 of the examination material, the substitutematerial is acceptable.6.4.1 All contrast sensitivity gauges shall be suitablymarked by vibro-engraving or etching. The gauge thicknessand material type shall be clearly marked.7. Imaging System Performance Levels7.1 Imaging system performance levels are designated by atwo-part measurement expressed as C − Umm. The firstpart of the expression C refers to the depth of theshallowest flat-bottom hole that can be reliably and repeatablyimaged. The second part of the expression refers to thecompanion system unsharpness measurement made with aresolution gauge expressed in terms of millimetres unsharp-ness. Where contrast sensitivity is measured for both thin andthick section performance, the performance level is expressedas Cmin–Cmax–U mm see Practices E1255 andE1734.7.2 Each contrast sensitivity gauge has four flat-bottomrecesses that represent 1 , 2 , 3 , and 4 of the gaugetotal thickness. The shallowest recess that can be repeatablyand reliably imaged shall determine the limiting contrastsensitivity.7.3 Contrast sensitivity measurements shall be made underconditions as nearly identical to the actual examination aspossible. Penetrating radiation energy, image formation,8Superston is a registered trademark of Superston Corp., Jersey City, NJ.9Inconel is a registered trademark of The International Nickel Co., Inc.,Huntington, WV 25720.10Monel is a registered trademark of The International Nickel Co., Inc.,Huntington, WV 25720.TABLE 1 Design of the Contrast Sensitivity GaugeGaugeThicknessJ Recess K Recess L Recess M RecessT 1ofT 2ofT 3ofT 4ofTTABLE 2 Contrast Sensitivity Gauge DimensionsGaugeSizeB DIM. C DIM. D DIM. E DIM. F,G DIM.1 0.750 in. 3.000 in. 0.250 in. 0.625 in. 0.250 in.19.05 mm 76.20 mm 6.35 mm 15.88 mm 6.35 mm2 1.500 in. 6.000 in. 0.500 in. 1.250 in. 0.500 in.38.10 mm 152.40 mm 12.70 mm 31.75 mm 12.7 mm3 2.250 in. 9.000 in. 0.750 in. 1.875 in. 0.750 in.57.15 mm 228.60 mm 19.05 mm 47.63 mm 19.05 mm4 3.000 in. 12.000 in. 1.000 in. 2.500 in. 1.000 in.76.20 mm 304.80 mm 25.40 mm 63.50 mm 25.4 mmTABLE 3 Contrast Sensitivity Gauge ApplicationGauge Size Use on Thicknesses1 Up to 1.5 in. 38.1 mm2 Over 1.5 in. 38.1 mm to 3.0 in. 76.2 mm3 Over 3.0 in. 76.2 mm to 6.0 in. 152.4 mm4 Over 6.0 in. 152.4 mmE1647 − 163processing, analysis, display, and viewing variables shallaccurately simulate the actual examination environment.8. Contrast Sensitivity Gauge Measurement Steps seeTable 18.1 The gauge thickness T shall be within 65 of theexamination object thickness value at which contrast sensitiv-ity is being determined.8.2 The gauge thickness tolerance shall be within 6 1ofthe gauge design thickness T or 0.001 in. 0.025 mm,whichever is greater.8.3 The gauge recess depth tolerance shall be within6 10 of the design value for the shallowe

注意事项

本文(ASTM E1647-16)为本站会员(Es前缘)主动上传,标准图书馆仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知标准图书馆(发送邮件至admin@stdlibrary.com或直接QQ联系客服),我们立即给予删除!

温馨提示:如果因为网速或其他原因下载失败请重新下载,重复下载不扣分。

关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服客服 - 联系我们

@copyright 2017-Stdlibrary All Rights Reserved.


收起
展开