1、Designation:D729806(Reapproved 2017)Standard Test Method forMeasurement of Comparative Legibility by Means ofPolarizing Filter Instrumentation1This standard is issued under the fixed designation D7298;the number immediately following the designation indicates the year oforiginal adoption or,in the c
2、ase 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 provides an objective means to com-paratively measure the ease of reading prin
3、ted matter for use inpackage labeling.1.2 This test method is not intended to quantify the legibilityof a printed item against a standard but to compare its legibilityagainst other items.1.3 This test method uses human subjects to view printedmatter mounted in a specialized instrument.1.4 The user o
4、f this test method must be aware that resultsmay differ from one age group of subjects to another.1.5 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 pr
5、actices and determine the applica-bility of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides a
6、nd Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D996 Terminology of Packaging and Distribution Environ-ments3.Terminology3.1 DefinitionsTerms and definitions used in this testmethod may be found in Terminol
7、ogy D996.3.2 Definitions of Terms Specific to This Standard:3.2.1 age groupsubjects are grouped by ages in a specifiedrange.3.2.2 analyzera moveable polarizing filter;the subjectoperates a hand wheel to rotate the analyzer(see Fig.1 and Fig.2).3.2.3 degrees of rotationthe angle of rotation of theana
8、lyzer where 0 is equivalent to no light transmission and 90is equivalent to full light transmission.3.2.3.1 DiscussionAt 0 rotation,the analyzer and polar-izer optical axes are perpendicular to one another.3.2.4 easellocated on top of the moveable stage;it is aplatform where printed matter is placed
9、 to be read(see Fig.1and Fig.2).3.2.5 hand cranka crank located at the front of theinstrument that adjusts the distance of printed matter bymoving the stage and easel.When it is rotated clockwise,itmoves the moveable stage closer to the subject,and when it isrotated counterclockwise it moves the sta
10、ge away from thesubject(see Fig.1 and Fig.2).3.2.6 hand wheela wheel subjects turn to rotate theanalyzer.Counterclockwise rotation increases the light trans-mitted and raises the legibility index.Clockwise rotationdecreases the light transmitted(see Fig.1 and Fig.2)andlowers the legibility index.3.2
11、.7 legibilitythe ease of deciphering or reading printedmatter,as measured by the legibility index in this test method.3.2.8 legibility indexthe name given to the degrees ofrotation of the analyzer,the reporting unit for the measurementof legibility.The first point where the printed matter becomeseas
12、y forthe subject to read.3.2.9 moveable stagea device topped with an easel that ismounted on a track within the legibility instrument that adjuststhe distance between the subject and the easel.3.2.10 polarizera fixed polarizing filter,mounted in theinstrument(see Fig.1 and Fig.2).3.2.11 subjectthe p
13、erson viewing the printed matter in theinstrument and controlling the rotation of the analyzer.3.2.12 testerthe person conducting the experiment.1This test method is under the jurisdiction of ASTM Committee F02 on PrimaryBarrier Packaging and is the direct responsibility of Subcommittee F02.50 onPac
14、kage Design and Development.Current edition approved Dec.15,2017.Published January 2018.Originallyapproved in 2006.Last previous edition approved in 2011 as D7298 06(2011)1.DOI:10.1520/D7298-06R17.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at s
15、erviceastm.org.For Annual Book of ASTMStandards volume information,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 StatesThis international standard was developed in accordance with
16、internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 3.2.13 training referenceAstandard message created in an8 point font.Subjects view the training reference before datacollection begins so that they become accustomed to theinstrument without affectingtest results.NOTE1*Analyzer and polarizer are
