ASTM_D_1155_-_10_2015.pdf

Designation:D115510(Reapproved 2015)Standard Test Method forRoundness of Glass Spheres1This standard is issued under the fixed designation D1155;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.Scope1.1 This test method2covers the determination of thepercent of true spheres in glass spheres used for retroreflectivemarking purposes and industrial uses.1.2 This test method includes two procedures as follows:1.2.1 Procedure A,in which the selected specimen is splitinto two size ranges or groups prior to separation into truespheres and irregular particles,and1.2.2 Procedure B,in which the selected specimen is splitinto five size ranges or groups prior to separation.1.2.3 Indeterminingcompliancewithspecificationrequirements,either Procedure A or Procedure B may be used.Where tests indicate failure to meet the specified percent oftrue spheres and irregular particles,the referee test shall bemade in accordance with Procedure B.1.3 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.4 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:3E11 Specification for Woven Wire Test Sieve Cloth and TestSievesE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method2.2 Other Document:ASTM MNL32 Manual on Test Sieving Methods3.Summary of Test Method3.1 The glass particles are mechanically separated into truespheres and irregular particles by controlled vibration on aglass plate fixed at a predetermined slope.4.Significance and Use4.1 The roundness of glass spheres is one measurable aspectrelating to their performance as a retroreflective media.Thefunction of this test method is to measure the percent of truespheres as related to compliance with applicable specifications.NOTE1This method has been used in other industrial areas outsidethe intended scope of this test method.5.Apparatus(Fig.1)5.1 Electrical Feeder-Vibrator,upon which is mounted asmooth glass panel,152.4 mm(6 in.)wide and 381 mm(15 in.)long.5.2 Hinged Base,supporting the vibrator and panel in sucha manner that the angle of slope of the glass panel with thehorizontal may be varied and fixed in any predeterminedposition.5.3 VibratorMeans of varying the amplitude or strength ofthe vibrations transmitted to the glass panel,at a fixedfrequency of 60 impulses per second.5.4 Feeding Device or Pan(Optional),affixed to the glasspanel in such a manner that the selected sample of glass maybe evenly dropped at a uniform rate upon the glass panel,fromvarious heights above the panel and at various points on theslope.5.5 Collecting Pans or Containers,at either end of thesloping panel,in which to collect the spheres and irregularparticles.5.6 Digital Level,approximately 30 to 60 cm(12 to 24 in.)in length(not shown).1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.44 on Traffic Coatings.Current edition approved June 1,2015.Published June 2015.Originallyapproved in 1951.Last previous edition approved in 2010 as D1155 10.DOI:10.1520/D1155-10R15.2For information on the development of this test method,reference may be madeto the paper by Keeley,A.E.,“Roundness Testing of Glass Spheres,”ASTMBulletin,No.174,May 1951,p.72.3For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Selection of Specimen6.1 Select a specimen of approximately 10 to 50 g of theglass spheres to be tested for roundness in one of the followingways:6.1.1 By mechanically splitting a bag or other container ofglass spheres,selected at random from the shipment to betested,or6.1.2 By grain or seed-rod selection from the container.6.1.3 The final sample for testing must be obtained using theappropriate sample splitters or reducers.Arrive as near aspossible to the desired sample quantity for testing by onlyusing this equipment.6.1.4 When there is a need to obtain the highest degree ofaccuracy possible the operator should use a sample size that isclosest to the 50 g size limit.In cases where there are disputesbetween the results obtain