ASTM_D_3252_-_73_1979_scan.pdf

=700927b 0028021 L b Designation:D 3252-73(Reapproved 1979)Nii Standard Test Method for UNDERSIZED LOOSE MUSCOVITE MICA s P LITTI N GS This Standard is issued under the fiexed designation D 3252;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.1.Scope 6.Procedure 1.i This method covers sampling and testing Grade No.6 loose mica Splittings for“under-size.”6.1 Thoroughly clean the drum and pan of 6.2 Obtain the tare weight of the pan,kO.1 all Splittings and particles.2.Summary of Method 2.I The test sample is placed in a perforated drum(Fig.i)and rotated for a specific time at a specified speed;the undersized particles are collected and weighed.3.Significance 3.1 The“percent undersize”obtained by this method(8.3.1)is an index or figure of merit;it is not an absolute value.This method is for use as a control and acceptance test.4.Apparatus 4.I Perforated Drum-A perforated drum 18 in.(457 mm)long and 15 in.(381 mm)in diameter,constructed of 0.025-in(0.64 mm)steel plate with perforations of 0.75 in.(19.1 mm)in diameter and an open area of 61+2%.It shall be driven by a constant-speed motor at the rate of 15 rpm(see Figs.I and 2).4 2 Beam Balance,having a sensitivity of 4.3 Catch Pan,0.0625 by 6.25 by 20 in.AO.1 g.(1.588 by 158.75 by 508 mm).S.Sampling 5.1 Take a minimum of I Ib(454 g)so as to be representating of the entire case for each case sampled.Sample at least 10%of the cases in a lot.5.2 Perform one test per sample.g.selected at randon from the sample.6.3 Weigh out 300 f 3 g of mica Splittings 6.4 Place the sample into the drum.6.5 Rotate the drum for 2 min at a rate of 15 rpm.6.6 Remove the catch pan with the under-sized Splittings and weigh,;t 0.1 g.7.Calculations tings as follows:(P-P)/S x 100 where:P=weight of the pan and particles,g,P“=tare weight of the pan,g,and S=weight of the sample,g.8.Report 7.1 Calculate the percent of undersized-split-8.1 The report shall include the following:8.1.I Lot and sample identification,8.I.2 Grade and type of mica,and 8.1.3 Percent of undersized Splittings.9.Precision and Accuracy precision and accuracy of this method.9.1 No data are available at this time on the This method IS under the JUriSdiCtion of ASTM Com-mittee D-Y on Electrical Insulating Materials and is the direct responaibiliiy of Subcommittee DWOY on Mica Products.Current edition approved Aug.27,1973.Published Sep-tember 1973.75 1 NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.-N I-V)W P.9009276 0028022 852 D 3252 I.Z 20 I;9009276 0028023 4 T i i D 3252 799 Fig.2 Photograph of Perforated Drum Assembly.The American Society for Testing and Materials takes no position respecting the validity of any patent rightr asserted in connection with any item mentioned in this standard.Users of this standard are express1 advised that determination of the validity of any such patent rights,and the risk of infiingement ofsuch rights,is entirely deir own respomibiliiy.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years and if not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters.Your comments will receive careful consideration at a meeting of the responsible technical committee,which you may attend.lfyou feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards,1916 Race St.,Philadelphia,Pa.19103,which will schedule a further hearing regarding your comments.Failing satisfaction there,you may appeal to the ASTM Board of Directors.753