1、Designation:F 1997 99Standard Test Method forDetermining the Sensitivity(Teasing)of a Tactile MembraneSwitch1This standard is issued under the fixed designation F 1997;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last
2、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 establishes procedures for depressingand releasing a tactile membrane switch to determine theamount of switch
3、teasing,if any.1.2 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.R
4、eferenced Documents2.1 ASTM Standards:2F 1570 Test Method for Determining the Tactile Ratio of aMembrane SwitchF 1597 Test Method for Determining the Actuation Forceand Contact Force of a Membrane Switch3.Terminology3.1 Definitions:Refer to Figs.1 and 2 for the followingterms.3.1.1 actuation force(F
5、max of Fa)maximum force mea-sured prior to or including point at which contact closure isachieved(see Test Method F 1597).3.1.2 break force(Fb)the force at contact break.3.1.3 break travel(Tb)the travel at contact break.3.1.4 circuit resistanceelectrical resistance as measuredbetween two termination
6、s whose internal contacts,when heldclosed,complete a circuit.3.1.5 contact breakpoint at which circuit resistance ishigher than specified resistance.3.1.6 contact closure(make)point at which specified re-sistance is achieved.3.1.7 contact force(Fc)the force at contact closure(seeTest Method F 1597).
7、3.1.8 contact travel(Tc)the travel at contact closure.3.1.9 Fminminimum force seen between Fmax and pointat which probe movement ceases.3.1.10 force-displacement curverelationship betweenforce applied and displacement of a membrane switch.Some-times referred to as“force-travel curve”.3.1.10.1 Discus
8、sionusually expressed as a line graph.3.1.11 force-resistance curvethe relationship betweenforce applied and resistance of a membrane switch.3.1.11.1 Discussionusually expressed as a line graph.3.1.12 membrane switcha momentary switching device inwhich at least one contact is on,or made of,a flexibl
9、esubstrate.3.1.13 nontactile switcha switch assembly that has atactile ratio equal to zero.3.1.14 return force(Frmin)minimum force seen duringreturn cycle before reaching Frmax.3.1.15 return max force(Frmax)maximum force mea-sured during return cycle after achieving Frmin.3.1.16 specified resistance
10、maximum allowable resistanceas measured between two terminations whose internal switchcontacts,when held closed,complete a circuit.3.1.17 switch teasing(break)the travel measurement onthe force-displacement curve between contact break(Fb)andreturn force(Frmin).3.1.18 switch teasing(make)the travel m
11、easurement onthe force-displacement curve between contact force(Fc)andminimum force(Fmin).3.1.19 tactile ratioa measure of tactile response(see TestMethod F 1570).3.1.20 tactile responsea sudden collapse or snapback of amembrane switch prior to contact closure or after contactbreak.3.1.21 tactile sw
12、itcha switch assembly that provides atactile ratio greater than zero.3.1.22 Tbtravel at contact break.3.1.23 Tfmtravel at Fmin.3.1.24 Trtravel at Fr.1This test method is under the jurisdiction of ASTM Committee F-1 onElectronics,and is the direct responsibility of Subcommittee F01.18 on MembraneSwit
13、ches.Current edition approved Dec.10,1999.Published February 2000.2For 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.
14、1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.FIG.1 Tease on MakeFIG.2 Tease on BreakF 1997 9923.1.25 Travel(displacement)distance traveled by the sur-face in contact with the test probe.4.Significance and Use4.1 The tendency of a switc
15、h to make or break electricalcontact at unexpected moments during closure or release canbe a sign of a poor design.The degree of teasing can rangefrom a simple annoyance to a failure of critical control process.4.2 The amount of switch sensitivity or teasing can also bea result of poor surface condu
16、ctivity that will prevent anelectrical event even when switch poles are in partial contact.5.Apparatus5.1 Test Probe:non-elastic,size and shape to be specified.5.2 Test Surface:flat,smooth,unyielding,and larger thanswitch under test.5.3 Device,to hold test probe securely and provide perpen-dicular movement into and away from switch under test.5.4 Resistance Measuring Device,that is ohm meter.Thedevice should not apply a voltage outside the operating rangeof the switch contacts.5.5 Suitable Monit