1、Designation:D4826 88(Reapproved 2007)An American National StandardStandard Practice forUnits of Measurement and Conversion Factors for Pulp,Paper,and Paperboard1This standard is issued under the fixed designation D4826;the number immediately following the designation indicates the year oforiginal ad
2、option 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 application of the InternationalSystem of Units(abbr
3、eviated SI)within the field of pulp,paper,and paperboard.The SI units have been adopted by ISO,ASTM,and TAPPI as the preferred units for use in theirstandards and test methods.1.2 Details of SI are given in various parts of ISO Stan-dards 31 and 1000,and in ASTM Practice IEEE/ASTM SI 10.Application
4、of this information is not always easy,as someproperties cannot at this time be expressed in SI,some can beexpressed in various units all within SI,and various multiplescan be used.Such variation can lead to confusion in reportingtest results and in quoting values for properties.1.3 In order to over
5、come such problems within the pulp,paper,and paperboard field,ISO/TC6 has recommended ap-propriate units in ISO Standard 5651.These recommendationsare reproduced in this practice,together with other informationand recommendations.2.Referenced Documents22.1 ASTM Standards:IEEE/ASTM SI 10 American Nat
6、ional Standard for Use ofthe International System of Units(SI):The Modern MetricSystem3,42.2ISO Standards:ISO 31 Quantities,Units and Symbols,Parts 0134ISO 1000SI Units and Recommendations for the Use ofTheir Multiples and of Certain Other Units43.Summary of Practice3.1 This practice covers the unit
7、s recommended for use inexpressing the properties of pulp,paper,and paperboard andother quantities found in the pulp,paper,and paperboarddocuments.It also provides the conversion factors for convert-ing customary units to metric units or other recommendedunits,and marks with an asterisk(*)when the c
8、onversionfactor is exact.3.2 Units recommended in ISO 5651 are marked(+)or(#),with the latter indicating that the recommended unit for pulp,paper,and paperboard is not a preferred SI unit.3.3 The international symbol for each unit is given in squarebrackets following the name of the unit.4.Significa
9、nce and Use4.1 Uniformity in expressing the results of testing and inquoting property values is needed for improved communica-tion in commerce and research.4.2 The table of recommended units and symbols and therules for using them provided in this practice will aid inachieving uniformity.5.Procedure
10、5.1 In converting from the customary units to the recom-mended form,multiply the test value expressed in customaryunits by the conversion factor to obtain the test value in therecommended form.As an example,suppose that the propertyof interest is the thickness of a sheet of paper,and that this hasbe
11、en determined to be 5.3 mils.Examination of the table showsthat in Section 1.2,Thickness,the conversion factor from milsto micrometres,is exactly 25.4.Multiplying 5.3 by 25.4,thetest value in the recommended units is 134.62 m.Generally,the converted value should be rounded to the same number ofsigni
12、ficant figures or one more than in the value in customaryunits,depending,respectively,on whether the first digit of thenew value is more or less than that of the original value.Thus,in this case,the converted value would be 135 m.NOTE1The rounding rule given here is easy to remember and doesnot resu
13、lt in the loss of significant information.For more detailedinformation on rounding,see Practice IEEE/ASTM SI 10.1This practice is under the jurisdiction of ASTM Committee D06 on Paper andPaper Products and is the direct responsibility of Subcommittee D06.92 on StandardDocuments Relating to Paper and
14、 Paper Products.Current edition approved April 1,2007.Published May 2007.Originallyapproved in 1988.Last previous edition approved in 2002 as D4826 88(2002).DOI:10.1520/D4826-88R07.2For the full titles of the standards and other documents listed in the table,seethe ISO,ASTM,and TAPPI indexes.3Availa
15、be from ASTM International,www.astm.org(Excerpts in Related Ma-terial section of all ASTM volumes.)4Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocke
16、n,PA 19428-2959,United States.NOTICE:This standard has either been superseded and replaced by a new version or withdrawn.Contact ASTM International(www.astm.org)for the latest information.5.2 If the property of interest had been the thickness ofcorrugated board of,for example,180 mils,the value would beconverted to millimetres,not micrometres.The conversionfactor is 0.0254 and the value in the recommended form is 4.57or 4.6 mm,depending on whether the zero in the last digit of180 is significant
