ASTM_D_669_-_03.pdf

Designation:D 669 03An American National StandardStandard Test Method forDissipation Factor and Permittivity Parallel with Laminationsof Laminated Sheet and Plate Materials1This standard is issued under the fixed designation D 669;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(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the dissi-pation factor and permittivity of stiff laminated sheet and plateinsulating materials in a direction parallel with the laminations.This test method primarily includes information covering thepreparation of the specimen,and details concerning the proce-dure required to make measurements parallel with the lamina-tions for this particular type of material.The apparatus andgeneral test procedure shall be in accordance with Test Meth-ods D 150.1.2 The values stated in inch-pound units are to be regardedas the standard.1.3 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.For a specificwarning statement see 9.2.2.Referenced Documents2.1 ASTM Standards:2D 150 Test Methods for AC Loss Characteristics and Per-mittivity(Dielectric Constant)of Solid Electrical Insula-tion3.Significance and Use3.1 It has long been recognized that dissipation factor andpermittivity of laminated insulation as measured in a directionperpendicular to the laminations are not of the same magnitudeas those measured parallel to the laminations.This test methodprovides a means of obtaining data parallel to the laminationswhere design parameters require this information.4.Selection of Test Specimens4.1 Select material for test that will not show obviousdefects in the area where the electrodes are to be applied unlessit is the purpose of this test to show the effects of such defectson the properties measured.5.Specimen Holder5.1 Construct a frame from38-in.(9.5-mm)square metalbars as shown in Fig.1.Mill slots 0.260 in.(6.60 mm)wideand116in.(1.6 mm)deep in two inner and opposite parallelsides of the frame to hold the test material in a parallel position.Insert threaded studs,equipped with nuts,in the open ends ofthe slotted bars to receive the(unmilled)clamping bars that areto be drawn tightly on the specimen pile-up.6.Electrodes6.1 Prepare two thin aluminum foil electrodes,2 to 4 in.(50to 100 mm)in diameter,depending on the frequency and thetype of circuit used in the measurement(see the Appendix ofTest Methods D 150).Preferably,use an electrode diameter sothat the capacitance measured is greater than 50 pF.Use ofsmaller diameter electrodes increases the effects of straycapacitances and decreases the precision of the measurements.7.Preparation of Test Specimens7.1 Cut strips of material 0.250+0.005 0.001 in.(6.35+0.013 0.003 mm)wide by 5.256 0.015 in.(133.35 60.38 mm)long in sufficient quantity to provide a pile-up ofabout 5.25 in.(134 mm)when stacked with the cut edgesexposed.7.2 Prepare two sets of test specimen pile-ups,one with thelong dimension in the machine direction of the material and theother in the cross-machine direction.Where the machinedirection of the paper-base or the warp direction of thefabric-base sheets is known,it shall constitute the length-wisedirection.Otherwise,consider the longer direction of the sheetmaterial the lengthwise direction.If the material sheet has thesame length and width,then arbitrarily designate one dimen-sion as the length.7.3 Mount the strips in the specimen holder with the uncutsurfaces adjacent to each other and the cut edges exposed.When testing thick sheets of material,it is permissible to1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.07 on Flexible and Rigid Insulating Materials.Current edition approved Oct.1,2003.Published November 2003.Originallyapproved in 1942.Last previous edition approved in 2002 as D 669 92(2002).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.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.reduce the width of the two outside strips to allow mounting inthe frame.Apply pressure to the strips by tightening the twonuts on the crossbar.This can be facilitated by laying theassembly on a flat surface so that the strips and not the frameare supported.Tightening the nuts in this position will ensurethat all cut surface