1、Designation: C838 96 (Reapproved 2010)1An 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,
2、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.1NOTEUpdated units of measurement throughout the standard editorially in May 2010.1. Scope1.1
3、 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 mate
4、rials that are thermally unstable at orbelow temperatures of 200C.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 i
5、s 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
6、 and Graphite Articles3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 bulk density, nthe mass of a unit volume includingboth permeable and impermeable voids (and boron compoundsin the case of boronated carbon or boronated graphite) presentin the material at room temperature.4.
7、 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 requir
8、ed.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
9、 is less than0.1 % weight loss. The drying temperature should be from 110to 200C.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)
10、.6. Procedure6.1 Logs or BlocksMeasure as-manufactured on the di-ameter 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, tw
11、o eachalong opposite faces. Make additional measurements, ifneeded, to determine a valid mean for each dimension. Makedimensional and mass measurements with equipment accurateto 0.5 %.36.2 Shaped ArticlesMake dimensional and mass measure-ments with equipment accurate to 0.5 %.7. Calculation7.1 Calcu
12、late the bulk density as follows:1This test method is under the jurisdiction of Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.F0 onManufactured Carbon and Graphite Products.Current edition approved May 1, 2010. Published May 2010. Originallyap
13、proved in 1980. Last previous edition approved in 2005 as C838 96 (2005).DOI: 10.1520/C0838-96R10E01.2For 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 D
14、ocument Summary page onthe ASTM website.3Corrections of mass measurements for buoyancy effects in air are generallynegligible for the accuracy obtained.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.D 5MVwhere:D = density, kg/m3,M =
15、 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 r
16、ight circular cylindersor rectangular parallelepipeds, the amount of volume correc-tion and method of calculation used in 5.2.9. Precision and Bias49.1 Precision:9.1.1 A machined steel mass and an unmachined graphitebillet, both right circular cylinders, were circulated to fivelaboratories. Each lab
17、oratory utilized two independent observ-ers, each making a replicate set of measurements. Also, eachlaboratory was instructed to use normal industrial practice, thatis, no special calibration or precaution. The data were testedagainst the null hypothesis (no difference between labs) and therandom ef
18、fects model for between-laboratory variance.9.1.2 Measurements on dimensions satisfied the null hy-pothesis with a pooled coefficient of variation of 0.25 % for thecalculated volume. Masses, and hence densities, did not satisfythe null hypothesis. Within-laboratory coefficient of variationon density
19、 was 0.28 % and between-laboratory coefficient was0.81 %. Although the between-laboratory data indicated a bias,subsequent rechecking failed to identify such.9.1.3 These precision measures represent normal industrialpractice and do not indicate the precision attainable undercontrolled conditions.9.2
20、 BiasNo statement on bias is derivable since the testswere performed with normal industrial practices and proce-dures.10. Keywords10.1 boronated; bulk; carbon; density; graphite; gravimet-ric; physicalASTM International takes no position respecting the validity of any patent rights asserted in conne
21、ction with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsi
22、ble technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful co
23、nsideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100
24、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:C05-1002.C838 96 (2010)12
