1、Designation:F254706(Reapproved 2013)Standard Test Method forDetermining the Attenuation Properties in a Primary X-rayBeam of Materials Used to Protect Against RadiationGenerated During the Use of X-ray Equipment1This standard is issued under the fixed designation F2547;the number immediately followi
2、ng 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 test method establish
3、es procedures for measuringthe attenuation of X-rays by protective materials at acceleratingpotentials from 60 to 130 kVp.1.2 This test method provides attenuation values of primarybeam X-radiation.1.3 This test method applies to both leaded and non-leadedradiation protective clothing materials.1.4
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.2.Referenced Documents
5、2.1 ASTM Standards:2F1494 Terminology Relating to Protective Clothing3.Terminology3.1 Definitions:3.1.1 attenuation,nFor radiological protective material,the reduction in the intensity of the X-ray beam resulting fromthe interactions between the X-ray beam and the protectivematerial that occur when
6、the X-ray beam passes through theprotective material.3.1.1.1 DiscussionIn this test method,the attenuation iscalculated as 1 minus the ratio of the measured exposure witha protective material in the beam to the measured exposurewithout the protective material in the beam at a specificaccelerating po
7、tential.Multiplying the resulting value by 100gives percent attenuation.Attenuationpercent!5S1 2exposure with sampleexposure without sampleD3100(1)3.1.2 lead equivalency,nFor radiological protectivematerial,the thickness in millimetres of lead(commonlydesignated mmPb)of greater than 99.9 percent pur
8、ity thatprovides the same attenuation as a given protective material.3.1.2.1 DiscussionThis test method provides the attenua-tion of the material and not the lead equivalency.Determininglead equivalency would require testing lead of known thicknessand purity,and comparing the attenuation of the prot
9、ectivematerial with the attenuation of the lead.Although leadequivalency has been the standard for reporting protectivematerial capability,the drafters of this test method believe it isnot feasible to obtain adequate standard lead samples forreporting lead equivalency values.3.1.3 secondary radiatio
10、n,nradiation outside the primaryX-ray beam.3.1.4 scatter radiation,na form of secondary radiationresulting from the interaction of the primary X-ray beam andthe target(for example,protective material being tested or apatient undergoing a medical procedure).3.1.5 half-value layer(HVL),nthe thickness
11、of aluminum,in millimetres(commonly designated mmAl),that reduces theintensity of the X-ray beam by one half.3.1.5.1 DiscussionThe HVLis dependent on the energy ofthe X-ray beam and,therefore,is different for X-rays producedat different accelerating potentials.3.1.6 kilovolts,peak(kVp),nthe maximum
12、electrical po-tential across an X-ray tube during an exposure,expressed inkilovolts.3.1.7 exposure,nfor radiological purposes,the amount ofionization in air at standard conditions caused by interactionwith X-rays,expressed in units of Roentgen(R)or milliroent-gen(mR).3.1.8 wave form ripple,nfor radi
13、ological purposes,thepeak-to-peak variation in the output voltage of the X-raygenerator.1This test method is under the jurisdiction ofASTM Committee F23 on PersonalProtective Clothing and Equipment and is the direct responsibility of SubcommitteeF23.70 on Radiological Hazards.Current edition approve
14、d July 1,2013.Published July 2013.Originally approvedin 2006.Last previous edition approved in 2006 as F2547-06.DOI:10.1520/F2547-06R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume inform
15、ation,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.9 ionization chamber,na device that measures theelectrical charge liberated during the ionization of air mol-ecules
16、by electromagnetic radiation(X-rays for the purposes ofthis test method),expressed in units of coulombs per kilogramof air.3.1.10 shielding,nfor radiological purposes,any materialor obstruction that attenuates radiation to protect personnel orequipment from the effects of ionizing radiation.3.1.11 coeffcient of variation,nthe ratio of the standarddeviation of a sample to the sample mean.3.1.12 For definitions of other terms related to protectiveclothing used in this test method,refer to Terminol
