ASTM_D_7298_-_06_2011e1.pdf

Designation:D729806(Reapproved 2011)1Standard 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 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.1NOTEMinor editorial corrections were made to Sections 3.2.5,3.2.6,and 7.3 in April 2011.1.Scope1.1 This test method provides an objective means to com-paratively measure the ease of reading printed 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 of 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 practices and determine the applica-bility of regulatory limitations prior to use.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 Terminology 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 theanalyzer 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 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 stage 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.3.2.7 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 becomeseasy 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 person viewing the printed matter in theinstrument and controlling the rotation of the analyzer.3.2.12 testerthe person conducting the experiment.3.2.13 training referenceAstandard message created in an8 point font.Subjects view the training reference before data1This test method is under the jurisdiction of ASTM Committee D10 onPackaging and is the direct responsibility of Subcommittee D10.32 on Consumer,Pharmaceutical and Medical Packaging.Current edition approved April 1,2011.Published April 2011.Originallyapproved in 2006.Last previous edition approved in 2006 as D7298 06.DOI:10.1520/D7298-06R11E01.2For 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 standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 collection begins so that they become accustomed to theinstrument without affectingtest results.NOTE1*Analyzer and polarizer are actually just inside the front wall of the instrument;subject looks through them using a shielded eyepiece(Seephoto in Fig.2).They are shown in the schematic to give researchers a clear idea of the instruments construction.FIG.1 Schematic of the Legibility InstrumentFIG.2 Photo of Legibility InstrumentD7298 06(2011)12 4.Summary of Test Method4.1 This test method describes a means for evaluating thelegibility of printed matter such as package labeling,printedinserts,and carton graphics by defining a standard procedurefor measuring the comparat