1、Designation: D 4892 89 (Reapproved 2009)An American National StandardStandard Test Method forDensity of Solid Pitch (Helium Pycnometer Method)1This standard is issued under the fixed designation D 4892; the number immediately following the designation indicates the year oforiginal adoption or, in th
2、e 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This
3、test method covers the determination of pitchdensity by helium pycnometer. It is applicable at a range ofroom temperatures of 15 to 35C.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to ad
4、dress 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:2D71 Test Met
5、hod for Relative Density of Solid Pitch andAsphalt (Displacement Method)D 2320 Test Method for Density (Relative Density) of SolidPitch (Pycnometer Method)D 2962 Test Method for Calculating Volume-TemperatureCorrection For Coal-Tar PitchesD 4296 Practice for Sampling PitchE11 Specification for Woven
6、 Wire Test Sieve Cloth andTest Sieves3. Terminology3.1 Definition of Term Specific to this Standard:3.1.1 density, as determined by this test methodthe massper unit volume and shall be reported as follows:density, 25C, g/cm3grams per cubic centimeter! (1)4. Summary of Test Method4.1 The sample is pu
7、lverized and screened to a givenfraction, then the volume of a weighed portion of the fractionis determined using a helium pycnometer.5. Significance and Use5.1 This test method is useful in characterizing pitches asone element in establishing uniformity of shipments andsources of supply. With this
8、method, the density is determinedto two decimal places, which is sufficient for most applications.If a more precise measurement is required (three decimalplaces), use Test Methods D 2320 or D71.6. Apparatus6.1 Helium Pycnometer.36.2 Balance, capable of weighing a 150-g specimen towithin 1 mg.6.3 Sie
9、ves, U.S. Standard 2.36-mm (No. 8), 600-m (No.30), conforming to Specification E11.6.4 Thermometer, for measuring room temperature.7. Bulk Sampling7.1 Samples from shipments shall be taken in accordancewith Practice D 4296 and shall be free of foreign substances.8. Dehydration8.1 All bulk samples su
10、spected of having free moistureshould be air-dried or oven-dried at 50C in a convection orforced-air oven before analyzing.9. Preparation of Test Specimen9.1 Crush a 50 to 200-g representative portion of the drypitch until all of it passes the 2.36 mm (No. 8 sieve). Avoid1This test method is under t
11、he jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.05 on Properties of Fuels, Petroleum Coke and Carbon Material.Current edition approved April 15, 2009. Published July 2009. Originallyapproved in 1989. Last previous edition
12、approved in 2004 as D 489289(2004).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.3Helium pycnometers availa
13、ble from the following suppliers have been foundsatisfactory for this purpose: (a) Beckman 2500 Harbor Blvd., Fullerton, CA, (b)Micromeritics, 5680 Goshen Springs Rd., Norcross, GA, and (c) Quantachrome, 5Aerial Way, Syosset, NY. If you are aware of alternative suppliers, please providethis informat
14、ion to ASTM International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee1, whichyou may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.grinding the pitch. Rem
15、ove the fines by screening through the600 m (No. 30 sieve) and use the pitch retained on this sieveas the test specimen.10. Calibration of Helium Pycnometer10.1 Calibrate daily or before using, following instrumentmanufacturers instructions.11. Procedure11.1 Place 10 to 150 g (80 to 90 % of the maxi
16、mum capacityof the particular holder being used) of the prepared crushed andsized fraction into the required specimen holder provided withthe instrument. Weigh to the nearest milligram.11.2 Determine volume of pitch following manufacturersinstructions.11.3 Weigh specimen container after determinatio
17、n; if thisweight is lower than the initial weight, the specimen has lostmoisture or volatiles during the density determination. Use thelower weight in determining the density. Also, if the specimenappears to have free moisture, dry the specimen as specified in8.1, and repeat the density determinatio
18、n.11.4 Record the room temperature during the density deter-mination.12. Calculation12.1 The procedure described in this test method determinesthe volume of a given mass of pitch at the ambient temperature(room temperature) of the helium pycnometer. Since thevolume of a given mass of pitch is temper
19、ature-dependent, thedensity of the given specimen will vary with the ambienttemperature. The variation of pitch volume with temperaturehas been previously established (Test Method D 2962 and theliterature4), and the following calculation corrects all densitymeasurements to 25C.12.2 The density of pi
20、tch, corrected to 25C, is given by thegeneral formula:d25C5WVt1 6 0.00047 Dt(2)where:W = specimen mass, g,Vt= volume of specimen, cm3, at measurement tem-perature,Dt = difference between 25C and the measurementtemperature, andd25C= pitch density at 25C, g/cm3.The factor 0.00047/C is obtained from th
21、e literature4andTest Method D 2962.12.3 Calculate the density of the pitch (to three decimalplaces) using the following equation:d25C5 VtWcorrection factor#(3)The correction factors for measurement temperatures of 15to 35C are given in Table 1.12.4 ExampleA specimen of pitch having a mass of20.027 g
22、 was found to have a volume of 15.26 cm3at atemperature of 30C; the density calculation is as follows:d25C520.027 g15.26 cm30.9985 1.315 g/cm3(4)12.5 Average duplicate results and round off to two decimalplaces.13. Report13.1 Report density of the pitch to two decimal places asfollows: density, 25C,
23、 g/cm3.14. Precision and Bias514.1 PrecisionThe following criteria shall be used for theacceptability of results (95 % probability):14.1.1 RepeatabilityDuplicate values by the same opera-tor shall not be considered suspect unless they differ by morethan 0.02.14.1.2 ReproducibilityThe values reported
24、 by each of twolaboratories, representing the arithmetic average of duplicatedeterminations, shall not be considered suspect unless thereported values differ by more than 0.03.14.2 BiasDuring the interlaboratory study to determinethe precision of this test method, the density was also deter-mined by
25、 Test Method D 2320 (water pycnometer). It wasfound that the density determined by helium pycnometer washigher than that determined by water pycnometer by anaverage value of 0.004.15. Keywords15.1 density; helium pycnometer; pitch4Mapstone, G. E., “Specific Gravity of Coal Tar Fractions,” Journal of
26、 AppliedChemistry, October 5, 1955, pp. 582588.5Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D08-1003.TABLE 1 Volume Correction Factors Versus MeasurementTemperatureMeasurement Temperature, C Correction Factor15 1.00516 1.004
27、17 1.00418 1.00319 1.00320 1.00221 1.00222 1.00123 1.00124 1.00025 1.00026 1.00027 0.99928 0.99929 0.99830 0.99831 0.99732 0.99733 0.99634 0.99635 0.995D 4892 89 (2009)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin
28、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 responsible technical committee and must
29、 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 consideration at a meeting of ther
30、esponsible 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 Barr Harbor Drive, PO Box C700,
31、 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).D 4892 89 (2009)3
