ASTM_F_205_-_94_2015.pdf

Designation:F20594(Reapproved 2015)Standard Test Method forMeasuring Diameter of Fine Wire by Weighing1This standard is issued under the fixed designation F205;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of the averagediameter of fine wire by weighing a known length;it appliesparticularly to sizes up to 0.13 mm used in electron devices andlamps.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 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:2F180 Test Method for Density of Fine Wire and Ribbon Wirefor Electronic Devices3.Apparatus3.1 The apparatus shall consist of a suitable torsion or otherdirect-reading balance capable of reading to 0.002 mg or 0.1%of the weight to be weighed(whichever is larger),with anaccuracy of 0.004 mg or 0.2%(whichever is larger).The rangeof the balance(or the size of the specimen)shall be such thatthe reading will lie within the upper half of the scale.4.Test Specimens4.1 Test specimens shall be selected at least 1 m from theend of a spool or sufficiently far from the end to be free fromkinks or other damage resulting in lack of straightness of thecut length.4.2 The wire shall be drawn from the spool under a loweven tension so that no elongation of the wire takes place.4.3 Each test specimen shall be cut to a length of 200 6 0.1mm.To prevent stretching,care shall be taken so that thetension is just sufficient to eliminate the sag and curl.Anydisagreement concerning the amount of tension to be used incutting shall be resolved between the manufacturer and thepurchaser.4.4 The test specimen shall be folded upon itself severaltimes and twisted to make a compact bundle with loopconsisting of a single strand for hanging it on the balancebeam.In the case of multiple specimens,all specimens shall betwisted together and hung by a loop consisting of a singlestrand.The specimen shall be handled as little as possible.Theoperators hands shall be clean and dry.5.Number of Specimens5.1 Weigh a single specimen if its weight lies within theupper half of the scale of the instrument.When the weight isless than half of the scale of the instrument,weigh a sufficientnumber of specimens,200 mm in length,simultaneously sothat the total weight will register in the upper half of the scale,preferably as close to the limit of the balance as possible.Usethe lowest range instrument compatible with the weight of the200-mm weight specimen to reduce the number of 200-mmlengths that must be weighed together.6.Repetition of Weighing6.1 If the corrected weight of a single specimen lies within60.5%of either the minimum or the maximum limit specifiedfor the wire weight,cut and weigh two more specimens of wirein a similar manner.When two or more lengths of wire havebeen weighed simultaneously to produce a reading in the upperhalf of the scale because of the small size of the wire,cut andweigh two more sets of specimens in a similar manner.7.Calibration and Checking of the Balance7.1 Check the balance regularly in accordance with therecommendations of the manufacturer.7.2 If a variety of weights are to be determined,calibrate thebalance at five major points on the scale and at zero bydetermining the weights of calibrated check weights.If anypoint is in error by more than 1%,remove the balance from1This test method is under the jurisdiction of ASTM Committee F01 onElectronicsand is the direct responsibility of Subcommittee F01.03 on MetallicMaterials,Wire Bonding,and Flip Chip.Current edition approved July 1,2015.Published September 2015.Originallyapproved in 1945 as B205 45 T.Last previous edition approved in 2010 as F205 94(2010).DOI:10.1520/F0205-94R15.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 service and repair it.Apply corrections determined by checkingto the apparent readings to obtain corrected weights.Obtaincorrections applied to apparent weights by interpolation be-tween the closest calibrated points,one above and one belowthe reading.7.3 If the amount of work to be weighed at one point on thescale justifies it,the balance may be calibrated with a standardweight(or combination of wei