ASTM_B_878_-_97_2014.pdf

Designation:B87897(Reapproved 2014)Standard Test Method forNanosecond Event Detection for Electrical Contacts andConnectors1This standard is issued under the fixed designation B878;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 method describes equipment and techniquesfor detecting contact resistance transients yielding resistancesgreater than a specified value and lasting for at least a specifiedminimum duration.1.2 The minimum durations specified in this standard are 1,10,and 50 nanoseconds(ns).1.3 The minimum sample resistance required for an eventdetection in this standard is 10.1.4 An ASTM guide for measuring electrical contact tran-sients of various durations is available as Guide B854.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 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 become familiarwith all hazards including those identified in the appropriateMaterial Safety Data Sheet(MSDS)for this product/materialas provided by the manufacturer,to establish appropriatesafety and health practices,and determine the applicability ofregulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2B542 Terminology Relating to Electrical Contacts and TheirUseB854 Guide for Measuring Electrical Contact Intermittences2.2 Other Standards:IEC 801-2 ed 2:913EN 50 082-1:9433.Terminology3.1 DefinitionsMany terms used in this standard are de-fined in Terminology B542.3.2 Definitions of Terms Specific to This Standard:3.2.1 event,na condition in which the sample resistanceincreases by more than 10 for more than a specified timeduration.4.Significance and Use4.1 The tests in this test method are designed to assess theresistance stability of electrical contacts or connections.4.2 The described procedures are for the detection of eventsthat result from short duration,high-resistance fluctuations,orof voltage variations that may result in improper triggering ofhigh speed digital circuits.4.3 In those procedures,the test currents are 100 mA(620mA)when the test sample has a resistance between 0 and 10.Since the minimum resistance change required to produce anevent(defined in 3.2.1)is specified as 10 (see 1.3),thevoltage increase required to produce this event must be at least1.0 V.4.4 The detection of nanosecond-duration events is consid-ered necessary when an application is susceptible to noise.However,these procedures are not capable of determining theactual duration of the event detected.4.5 The integrity of nanosecond-duration signals can onlybe maintained with transmission lines;therefore,contacts inseries are connected to a detector channel through coaxialcable.The detector will indicate when the resistance monitoredexceeds the minimum event resistance for more than thespecified duration.4.6 The test condition designation corresponding to a spe-cific minimum event duration of 1,10,or 50 ns is listed inTable 1.These shall be specified in the referencing document.1This test method is under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and is the direct responsibility of SubcommitteeB02.11 on Electrical Contact Test Methods.Current edition approved Oct.1,2014.Published October 2014.Originallyapproved in 1997.Last previous edition approved in 2009 as B878 97(2009).DOI:10.1520/B0878-97R14.2For 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.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.Apparatus5.1 DetectorThe detector used shall be an AnaTech 64EHD,32 EHD,or equivalent.The detector shall meet thefollowing requirements:5.1.1 Electromagnetic Interference(EMI)The detectorshall pass the European Community(EC)electrostatic dis-charge(ESD)requirement for computers(EN 50 082-1:94based on IEC 801-2,ed.2:91).The performance criteria is“1)normal performance within the specification limits;”that is,nochannel is allowed to trip.Air discharge voltages shall include2,4,8,and 15 kV.Contact discharge voltages shall include 2,4,6,and 8 kV.Detector inputs shall be protected with coaxialshorts.5.1.2 dc CurrentEach channel shall supply 100 6 20 mAwhen the sample being tested has a resistance between 0 and 10.5.1.3 Input Impedance:5.1.3.1 Direct Current(dc)The detector source resistance(impedance)shal