1、Designation:D 4826 88(Reapproved 2002)An American National StandardStandard Practice forUnits of Measurement and Conversion Factors for Pulp,Paper,and Paperboard1This standard is issued under the fixed designation D 4826;the number immediately following the designation indicates the year oforiginal
2、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.1.Scope1.1 This practice covers the application of the InternationalSystem of Units(a
3、bbreviated 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 Standard E 380.Applicationof this
4、information is not always easy,as some propertiescannot at this time be expressed in SI,some can be expressedin various units all within SI,and various multiples can beused.Such variation can lead to confusion in reporting testresults and in quoting values for properties.1.3 In order to overcome suc
5、h 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 National St
6、andard 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 units recomm
7、ended 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 conversio
8、nfactor 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.Significance and
9、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.Procedure5.1 In c
10、onverting 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 hasbeen deter
11、mined 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 ofsignificant f
12、igures 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 result in th
13、e loss of significant information.For more detailedinformation on rounding,see ASTM Practice E 380.5.2 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
14、 in the recommended form is 4.571This practice is under the jurisdiction of ASTM Committee D06 on Paper andPaper Products and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved May 27,1988.Published July 1988.2For the full titles of the standards and other do
15、cuments listed in the table,seethe ISO,ASTM,and TAPPI indexes.3Availabe from ASTM International,www.astm.org(Excerpts in Related Ma-terial section of all ASTM volumes.)4Available from American National Standards Institute,25 W.43rd St.,4thFloor,New York,NY 10036.1Copyright ASTM International,100 Bar
16、r Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.or 4.6 mm,depending on whether the zero in the last digit of180 is significant or simply holding the decimal place.5.3 Generally,if the table allows a choice in the recom-mended form,choose that form that would have no more thanthree significant figures in front of the decimal point for mostof the values and only one place after the decimal point.However,use,for example,0.13 mm,not 130 m,if the zeroin 130 is not significant
