ASTM_D_6101_-_97.pdf

Designation:D 6101 97An American National StandardStandard Test Method forEquivalent Black Area(EBA)of Dirt in Pulp,Paper andPaperboard by Image Analysis1This standard is issued under the fixed designation D 6101;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(e)indicates an editorial change since the last revision or reapproval.INTRODUCTIONThe level of visible dirt present in pulp,paper or paperboard can impact its usefulness in a specificend use application.In such cases,the presence of visible dirt specks that are high in number,easilynoticed in visual examination,or both,may detract more from the apparent usefulness of the papermaterial than does a lower number of specks,or specks that are less easily noticed by the eye.Boththe number of dirt specks and their visual impact may be important.For someone controlling ormonitoring the papermaking process,the absolute physical area of dirt,or the number of dirt speckspresent in an inspection area may be of greatest importance.For the end user of the paper material,the overall visual impression may be the critical parameter.1.Scope1.1 This test method covers the use of image analysis todetermine the level of dirt in pulp,paper,and paperboard interms of Equivalent BlackArea(EBA)of dirt specks within thephysical area range of 0.02 to 3.0 mm2reported in parts permillion as well as the number of dirt specks per square meterof sample.Using the algorithm prescribed in this test method,the maximum dirt size is limited to 3.0 mm2.Extention to otherspeck sizes(for example those greater than 3.0 mm2in physicalarea),may require changes in equipment,calculation proce-dures,or both,and is not covered in this test method.This testmethod cannot be used for physical area measurements since itdoes not correctly measure the dirt specks for that mode ofmeasurement.1.2 The specimen to be evaluated must have a brightness,asdetermined by Test Method D 985,of 30%or greater.It maybe necessary to reform some pulp sheets into handsheets if thesurface is too rough or textured.1.3 This test method is an instrumental equivalent of TestMethod D 2019,TAPPI T 437,and TAPPI T 213,all three ofwhich report the equivalent black area of dirt in parts permillion,and TAPPI T 537,which reports the number of specksof 0.02 mm2or larger per square meter.This test method can beimplemented using any image analysis system,provided that itmeets the criteria specified herein.2.Referenced Documents2.1 ASTM Standards:D 585 Practice for Sampling and Accepting a Single Lot ofPaper,Paperboard,Fiberboard,and Related Products2D 985 Test Method for Brightness of Pulp,Paper,andPaperboard(Directional Reflectance at 457 nm)2D 2019 Test Method for Dirt in Paper and Paperboard2E 122 Practice for Choice of Sample Size to Estimate aMeasure of Quality for a Lot or Process32.2TAPPI Standards:4T 213 Dirt in PulpT 272 Forming handsheets for reflectance testing of pulp(sheet machine procedure)T 437 Dirt in Paper and PaperboardT 537 DirtCountinPaper(OpticalCharacterRecognitionOCR)T 1206 Precision Statement for Test Methods3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 dirt,nany foreign matter embedded in or on thesheet,which,when examined by reflected light has a contrast-ing,darker color to the sheet surface and has an equivalentblack area of 0.02 mm2or greater as determined by this testmethod.1This test method is under the jurisdiction of ASTM Committee D-6 on Paperand Paper Products and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved July 10,1997.Published March 1998.2Annual Book of ASTM Standards,Vol 15.09.3Annual Book of ASTM Standards,Vol 14.02.4Available from TAPPI,Technology Park,P.O.Box 105113,Atlanta,GA30348-5113.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.3.1.2 equivalent black area(EBA),nthe area of one of theround black spots(brightness of 2.4%measured by TestMethod D 985)on the TAPPI Dirt Estimation Chart that hasthe same apparent area when examined visually upon its whitebackground(brightness of 81.5%measured by Test MethodD 985)as does the dirt speck when examined visually upon theparticular sheet in or upon which it is embedded.3.1.2.1 DiscussionAlarger“gray”dirt speck has the samevisual impact as a smaller“black”one when viewed on thesame sheet and under the same conditions.The equivalentblack area(EBA)of a dirt speck determined visually isgenerally less than its physical area.The EBA approaches thephysical area only as the speck becomes large.This definitionof EBA is technically identical to that found in Test MethodD 2019,T 213 and T 437,and this test method produces resultsthat are the technical equivalent of those test methods.4.Significance and Use4.1 The visual impact of a dark speck on a light backgr