1、Designation: D2947/D2947M 88 (Reapproved 2011)1Standard Test Method forScreen Analysis of Asbestos Fibers1This standard is issued under the fixed designation D2947/D2947M; the number immediately following the designation indicates theyear of original adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEUnits information was editorially corrected in February 2012.1. Scope1.1 This test method covers a dry screen analysis foras
3、bestos fiber by means of a mechanical sieve shaker.1.2 This test method is limited in its application to Group 4and shorter chrysotile asbestos fiber samples2as defined in TestMethod D3639. However, some short amphibole asbestosfibers may be suitable for evaluation by this method.1.3 The values stat
4、ed in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.4 Wa
5、rningBreathing of asbestos dust is hazardous.Asbestos and asbestos products present demonstrated healthrisks for users and for those with whom they come into contact.In addition to other precautions, when working with asbestos-cement products, minimize the dust that results. For informa-tion on the
6、safe use of chrysoltile asbestos, refer to “Safe Useof Chrysotile Asbestos: A Manual on Preventive and ControlMeasures.”31.5 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-p
7、riate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific safetyhazard, see 1.4.2. Referenced Documents2.1 ASTM Standards:4D2590 Test Method for Sampling Chrysotile AsbestosD2946 Terminology for Asbestos and AsbestosCementProductsD3639 Te
8、st Method for Classification of Asbestos by Que-bec Standard TestD3879 Test Method for Sampling Amphibole Asbestos5E11 Specification for Woven Wire Test Sieve Cloth and TestSievesE177 Practice for Use of the Terms Precision and Bias inASTM Test Methods3. Summary of Method3.1 The procedure consists o
9、f screening a test specimenthrough a specified nest of sieves by means of a mechanicalsieve shaker that reproduces the circular and tapping motiongiven testing sieves in hand-sieving, but with a uniform,mechanical action, assuring more accurate and dependabletests.4. Significance and Use4.1 Test res
10、ults give some indication of the apparent fiberlength distribution in the sample tested.4.2 Sieves are ideally suited to measure particle size andparticle size distribution when all three axes of the particle areequidimensional or the particle is of spherical shape. Asbestosfibers differ considerabl
11、y from these ideal conditions and,therefore, results depart from a true measure of fiber length andlength distribution.1This method is under the jurisdiction of ASTM Committee C17 on Fiber-Reinforced Cement Products and is the direct responsibility of SubcommitteeC17.03 on Asbestos - Cement Sheet Pr
12、oducts and Accessories.Current edition approved Nov. 1, 2011. Published February 2012. Originallyapproved in 1971. Last previous edition approved in 2006 as D2947 88 (2006).DOI: 10.1520/D2947_D2947M-88R11E01.2Quebec Asbestos Mining Assn. (QAMA) standard designation of chrysotileasbestos grades.3Avai
13、lable from The Asbestos Institute, http:/ 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.5Withdrawn. The last app
14、roved version of this historical standard is referencedon www.astm.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3 Characteristics that influence screening efficiency influ-ence test results. Among these are moisture content,
15、 degree offiberization, harshness, and the tendency for fibers to clingtogether, and of short fibers and fines to cling to longer fibers.4.4 In spite of its shortcomings, this test method is particu-larly useful because of its simplicity and speed and satisfactoryreproducibility.4.5 The test is suit
16、able for specification acceptance andmanufacturing control.5. Apparatus5.1 Sieve Shaker6for 200-mm 8-in. diameter sieves thatimpart the screening and tapping action found necessary forthis asbestos application.5.1.1 The shaker shall be mounted on a suitable firmfoundation, preferably concrete.5.1.2
17、The eccentric shaft shall rotate at a speed of 285 6 5r/min. The machine shall be geared to give 152 taps/min whenthe eccentric shaft rotates at 285 r/min.5.1.3 The plate supporting the nest of sieves must be set togive a clearance of 2.4 6 0.8 mm 332 6132 in. between thetop of the cast iron cover a
18、nd the bottom of the stops on thecarrying plate (dimension A in Fig. 1). This clearance issufficient to allow the nest of sieves to be easily set in place andto rotate freely when the shaker is in operation. It is importantthat this gap be checked periodically in order to maintainproper sieving acti
19、on.5.1.4 The cast iron cover for the nest of sieves shall be fittedwith a standard No. 9 rubber stopper made of neoprene or otherelastomer of equal elasticity.5.1.5 The height of the stopper above the top of the cast ironcover plate shall be 25.4 6 3.2 mm 1 618 in. (dimension Aplus B in Fig. 1) meas
20、ured with the hammer resting on thestopper. With a new stopper this measurement should be takenonly after the machine has been in operation for a few hoursand should be set as closely as possible to the maximum settingof 28.6 mm 118 in.5.1.6 The center of the hammer is a point in the center of thefa
21、ce 244.5 6 0.4 mm 958 6164 in. from the center of thehammer pin. The hammer drop, measured from the center ofthe hammer in its highest position to the top of the stopper,shall be 34.9 6 3.2 mm 138 618 in. The hammer drop maybe adjusted by adjustments in the top end of the push rod (Fig.2) or adjustm
22、ents in the location of the push rod collar, or byboth adjustments. A minimum clearance of 1.6 mm 116 in.between the push rod and the hammer in its lower position(dimension E in Fig. 1) should be maintained.5.1.7 Automatic Timer or Timeswitch to energize the shakerwith an accuracy of 65 s, on period
23、s extending from 10 to 30min.5.2 Sieves:5.2.1 Standard 20 cm 8-in. diameter covers, sieve frames,and pans shall be used. Sieve frames and pans shall be fullheight. Wire cloth of sieves, covers, frames and pans shallconform to Specification E11, except that stainless steel may beused in place of shee
24、t brass if desired.Alternatively, equivalentTyler Standard Sieves may be used.5.2.2 If calibration and standardization are desired, proceedas in the appendixes to Specification E11.6. Sampling6.1 Select samples in accordance with Test Method D2590for chrysotile fibers or Test Method D3879 for amphib
25、ole6The Tyler Ro-Tap has been found satisfactory for this purpose. The criteria,settings, and adjustments specified in 5.1.2 to 5.1.6 have been found to providereproducible results with this unit. Any other mechanical shaker that imparts to thenest of sieves a motion identical to that of this device
26、, and that can reproduce resultsachieved with the Ro-Tap would be acceptable as being equivalent thereto. If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible techn
27、ical committee,1which you may attend.FIG. 1 Sieve ShakerD2947/D2947M 88 (2011)12fibers. If in doubt as to the type of fiber refer to the detaileddescriptions of chrysotile and of commercially importantamphibole fibers given in Terminology D2946.(Warningsee 1.4.)7. Test Specimens, Screen Sizes and Te
28、st Duration7.1 The sample size, series of sieves, and test duration forthe particular grade to be tested are shown in Table 1.8. Procedure8.1 Select a series of sieves corresponding to the grade offiber to be tested as listed in Table 1.8.2 Nest the sieves in the order of decreasing opening sizeswit
29、h the coarsest size on top, and a pan at the bottom.8.3 Weigh the specimen to the mass indicated in Table 1 andplace it on the uppermost sieve and close it with a sieve cover.8.4 Set the cast iron cover in place on top of the sieve cover.8.5 Place the sieve assembly in the shaker and lock it inposit
30、ion.8.6 Start the sieve shaker and run it for the test durationspecified in Table 1.8.7 When the shaker has stopped, remove the sieves andweigh the contents of each to the nearest 0.1 g.9. Report9.1 Record the analysis in tabular form as the percentage bymass of material retained on each individual
31、sieve and in thepan. Report the average of two acceptable results as defined in10.4.1.9.1.1 The particular sieve designation used or the nominalopening of each sieve shall be clearly indicated.9.2 In addition, results may also be presented as cumulativepercent retained, cumulative percent passing, o
32、r by graphicalrepresentation.9.3 Fully identify the sample as to origin and grade desig-nation.9.4 If screen blinding or the formation of agglomerations ofany kind due to the shaking action are encountered, remarks tothis effect must be included in the report.10. Precision and Bias10.1 Repeatability
33、The single-operator, single apparatusrepeatability is presented in Table 2 based upon five and tworeplicates. The latter is significant because two replicates arecalled for by this test method.10.2 Reproducibility, (as defined in Practice E177).10.2.1 The intralaboratory multiple operator, apparatus
34、 andsample variation between two test results should not exceed thevalues presented in Table 3 in 95 % of cases.10.2.2 During the period 1961 to 1975, a fifteen year annualintralaboratory reproducibility study was carried out on 15different samples of each of 91 chrysotile grades using multipleopera
35、tors and apparatus. The ranges of statistics presented inTable 4 were obtained. The reproducibilities expressed ascoefficients of variation are presented in Table 5 for each sieveand for each group of fibre grades.10.3 Bias:10.3.1 Bias cannot be established on asbestos fiber for lackof a suitable re
36、feree method.10.3.2 Bias associated with each of the sieves used may bedetermined as described in the appendices to Specification E11.10.3.3 It has been observed that the retention of the fibers oneach sieve may be a function of the degree to which the screencloth is worn.10.4 Acceptance of Test Res
37、ults:10.4.1 The acceptable variation in the cumulative total ofthe fractions weighed may not exceed 61.0 %. In such a case,repeat the test.11. Keywords11.1 asbestos; fiber; fiber length distribution; Ro-Tapscreen; screen analysis; sievingFIG. 2 Adjustable Push RodD2947/D2947M 88 (2011)13TABLE 1 Siev
38、e Sizes, Specimen Mass and Test DurationGradeA4 5 6 and 7D 7 except 7DSieve series, mm 6.73 . . .4.76 4.76 . .3.36 3.36 3.36 3.361.68 1.68 1.68 . . 1.19 1.19Sieve series, m 841 841 841 841. . . 595420 420 420 420. 210 210 210pan pan pan panSpecimen Mass, g 50 6 0.05 50 6 0.05 100 6 0.05 100 6 0.05Te
39、st Duration, min 10 10 10 30Equivalent Sieve SeriesSI Sieve Openings US Standard Series AlternativeSieve DesignationTyler Series MeshDesignationmm m6.73 0.265 in. 34.76 No. 4 43.36 661.68 12 101.19 16 14. 841 20 20. 595 30 28. 420 40 35. 210 70 65AQuebec Asbestos Mining Association.TABLE 2 Repeatabi
40、litySieve OpeningmmRepeatability, %Minimum Maximum5 Replicates2Replicates5 Replicates 2 Replicates6.73 0.71 1.6 22.7 51.24.76 0.78 1.8 6.6 15.23.36 0.92 2.0 5.9 12.81.68 0.77 1.7 5.6 12.41.19 1.74 3.9 8.4 18.8841 m 0.82 1.8 4.4 9.7595 m 0.60 1.3 3.5 7.6420 m 0.33 0.7 0.8 1.7210 m 0.72 1.6 3.6 8.0TAB
41、LE 3 ReproducibilitySieveOpening, mmReproducibility, %Minimum Maximum5 Replicates 2 Replicates 5 Replicates 2 Replicates6.73 0.80 1.6 25.6 51.24.76 1.83 2.4 15.5 20.33.36 1.46 2.3 9.3 14.71.68 2.36 2.8 17.1 20.31, 19 1.19 3.7 5.8 18.0841 m 0.47 1.7 2.5 9.0595 m 1.66 2.0 9.6 11.6420 m 0.43 0.8 1.0 1.
42、9210 m 1.35 2.0 6.7 9.9D2947/D2947M 88 (2011)14ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights,
43、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 be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revi
44、sion of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you
45、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, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be o
46、btained 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/).TABLE 4 Ranges of Rep
47、roducibility StatisticsGrades and Quantity of SamplesSieve MeshmmRange % retained Standard Deviation, % Variance range, %min max min max min maxGroup 4 6.73 1.2 3.7 0.7 2.0 54.0 90.014 samples 4.76 2.3 16.1 0.6 3.25 14.9 61.53.36 9.6 21.7 1.5 2.7 7.4 26.51.68 29.4 42.6 1.0 8.3 2.4 28.2841 m 13.0 26.
48、0 1.2 2.3 5.5 11.5420 m 4.6 15.8 0.7 2.0 7.6 17.8pan 4.4 11.6 0.8 2.6 13.7 25.6Group 5 4.76 0.4 3.8 0.4 2.3 44.4 79.722 samples 3.36 0.45 15.4 0.35 3.5 12.3 85.71.68 26.6 50.0 1.7 12.2 4.0 25.6841 m 14.4 36.7 1.3 7.8 5.4 28.0420 m 7.0 21.6 0.6 4.1 6.2 21.0210 m 2.5 5.5 0.3 1.1 7.3 22.4pan 3.4 14.4 0
49、.7 2.9 14.0 28.1Group 6 and 7D 3.36 0.3 1.2 0.1 1.1 33.2 91.713 samples 1.68 8.6 27.4 1.9 6.2 13.8 36.51.19 14.6 26.8 1.1 2.6 5.8 14.4841 m 16.6 23.2 1.0 2.6 4.7 14.2420 m 20.7 33.6 2.0 3.0 6.7 13.0210 m 4.5 9.4 0.7 1.7 10.4 28.9pan 5.1 16.9 0.8 3.5 11.1 38.9Group 7 except 7D 3.36 0 0 0 0 0 042 samples 1.19 0 3.6 0 2.8 0 120841 m 0 12.8 0 2.6 0 100595 m 0 28.8 0 3.8 0 100420 m 1.6 38.0 0.7 7.6 4.2 76210 m 7.3 64.8 0.7 9.7 4.9 26pan 11.9 67.7 1.5 9.8 2.6 28TABLE 5 Reproducib
