ASTM_C_838_-_16.pdf

Designation:C83816An American National StandardStandard Test Method forBulk Density of As-Manufactured Carbon and GraphiteShapes1This standard is issued under the fixed designation C838;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.1.Scope*1.1 This test method covers the determination of the densityof as-manufactured carbon and graphite from measurements ofmass and dimensions at room temperature.1.2 This test method is applicable to boronated carbon andgraphite.1.3 This test method is not applicable to carbon-andgraphite-containing materials that are thermally unstable at orbelow temperatures of 200 C.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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:2C559 Test Method for Bulk Density by Physical Measure-ments of Manufactured Carbon and Graphite Articles3.Terminology3.1 Definitions:3.1.1 bulk density,nin carbon and graphite technology,the mass of a unit volume including both permeable andimpermeable voids(and boron compounds in the case ofboronated carbon or boronated graphite)present in the materialat room temperature.4.Significance and Use4.1 This test method provides a means of determining bulkdensity on as-manufactured logs,blocks,or shaped articles.4.2 This test method is suitable for manufacturing controland acceptance specifications.4.3 Test Method C559 may be used when a higher degree ofaccuracy is required.5.Test Specimens5.1 Logs or BlocksMay be measured and weighed as-manufactured or after rough ends have been squared bymachining.The stock shall preferably have been indoors afterheat treatment;if there is doubt that the piece is dry,weigh,dry,and reweigh it.Repeat,if necessary,until there is less than0.1%weight loss.The drying temperature should be from110 C to 200 C.5.2 Shaped ArticlesOther than right circular cylinders orrectangular parallelepipeds may be measured,and a correctionmade for the cavities or protuberances if the specimen volumecan be determined within 0.5%(see 6.2).6.Procedure6.1 Logs or BlocksMeasure as-manufactured on the diam-eter or cross section at two different locations,taking care toavoid distortions.Take four length measurements on cylinders90 apart on the periphery of the circular end faces.Onrectangular pieces,make four length measurements,two eachalong opposite faces.Make additional measurements,ifneeded,to determine a valid mean for each dimension.Makedimensional and mass measurements with equipment accurateto 0.5%.NOTE1Corrections of mass measurements for buoyancy effects in airare generally negligible for the accuracy obtained.6.2 Shaped ArticlesMake dimensional and mass measure-ments with equipment accurate to 0.5%.7.Calculation7.1 Calculate the bulk density as follows:D 5MV1This test method is under the jurisdiction of Committee D02 on PetroleumProducts,Liquid Fuels,and Lubricants and is the direct responsibility of Subcom-mittee D02.F0 on Manufactured Carbon and Graphite Products.Current edition approved Jan.1,2016.Published February 2016.Originallyapproved in 1980.Last previous edition approved in 2010 as C838 96(2010)1.DOI:10.1520/C0838-16.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 where:D=density,kg/m3,M=mass,kg,andV=volume,m3.7.2 Calculate to three significant figures.8.Report8.1 Report the following:8.1.1 Type,source,grade,geometry,and whether the speci-men is as-manufactured or machined.8.1.2 Densities of the individual specimens and the aver-ages.8.1.3 On shaped articles,other than right circular cylindersor rectangular parallelepipeds,the amount of volume correc-tion and method of calculation used in 5.2.9.Precision and Bias39.1 Precision:9.1.1 A machined steel mass and an unmachined graphitebillet,both right circular cylinders,were circulated to fivelaboratories.Each laboratory utilized two independentobservers,each making a replicate set of measurements.Also,each laboratory was instructed to use normal industrialpractice,that is,no special calibration or precaution.The datawere tested against the null hypothesis(no difference betweenlabs)and the random effects mode