ASTM F1997-1999(2005) Standard Test Method for Determining the Sensitivity (Teasing) of a Tactile Membrane Switch《触觉薄膜开关敏感度测定(针拨开法)的标准试验方法》.pdf

1、Designation: F 1997 99 (Reapproved 2005)Standard 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 rev

2、ision, 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 establishes procedures for depressingand releasing a tactile membrane switch to d

3、etermine theamount of switch 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 regula

4、tory limitations prior to use.2. Referenced 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 f

5、ollowingterms.3.1.1 actuation force (Fmax 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 resi

6、stance as measuredbetween two terminations 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 for

7、ce at contact closure (seeTest Method F 1597).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 re

8、ferred to as “force-travel curve”.3.1.10.1 Discussionusually 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 inwhic

9、h at least one contact is on, or made of, a flexiblesubstrate.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 cy

10、cle after achieving Frmin.3.1.16 specified resistancemaximum 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) andr

11、eturn force (Frmin).3.1.18 switch teasing (make)the travel measurement 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

12、prior to contact closure or after contactbreak.3.1.21 tactile switcha 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 F01 onElectronics , and i

13、s the direct responsibility of Subcommittee F01.18 on MembraneSwitches.Current edition approved Jan. 1, 2005. Published January 2005. Originallyapproved in 1999. Last previous approved in 1999 as F 199799.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer S

14、ervice 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.FIG. 1 Tease on MakeFIG. 2 Tease on Break

15、F 1997 99 (2005)23.1.25 Travel (displacement)distance traveled by the sur-face in contact with the test probe.4. Significance and Use4.1 The tendency of a switch to make or break electricalcontact at unexpected moments during closure or release canbe a sign of a poor design. The degree of teasing ca

16、n 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 conductivity that will prevent anelectrical event even when switch poles are in partial contact.5. Apparatus5.1 Test Probe: non-elastic, size an

17、d 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 volta

18、ge outside the operating rangeof the switch contacts.5.5 Suitable Monitoring Device, to measure force on testprobe.5.6 Suitable Monitoring Device, to measure travel.6. Procedure6.1 Pre-Test Setup:6.1.1 Secure switch on test surface.6.1.1.1 Precondition switch by depressing manually 25times.6.1.2 Pos

19、ition test probe over desired area of switch.6.1.3 Connect switch terminals to resistance measuringdevice.6.1.4 Zero gages.6.1.5 Lower probe until tip is just above top surface ofswitch without touching.6.2 In-Process Test:6.2.1 Begin by activating test probe movement down at arate not to exceed 13

20、mm/s.6.2.2 Monitor force and resistance during probe movement.6.2.3 During probe movement record Fmax and Fmin.6.2.4 Record Tfm (travel at Fmin).6.2.5 Monitor resistance during probe movement and notewhen specified resistance is achieved:6.2.5.1 Record force on probe as Fc.6.2.5.2 Record travel as T

21、c.6.2.6 Continue probe movement downward until probemovement stops or when force on probe is a minimum of110 % of Fmax.6.2.7 Reverse direction of test probe at a rate not to exceed13 mm/s.6.2.8 Record Frmin and Tr.6.2.9 Monitor resistance during probe movement and notewhen resistance is higher than

22、the specified resistance and:6.2.9.1 Record force on probe as Fb, and6.2.9.2 Record travel as Tb.7. Calculation7.1 Determine switch teasing at make:7.1.1 Travel switch tease (make) = Tc Tfm7.1.2 Force switch tease (make) = Fc Fmin7.2 Determine switch teasing at break:7.2.1 Travel switch tease (break

23、) = Tb Tr7.2.2 Force switch tease (break) = Fb Frmin8. Report8.1 Report the following information:8.1.1 Travel switch tease (make).8.1.2 Force switch tease (make).8.1.3 Travel switch tease (break).8.1.4 Force switch tease (break).8.1.5 Temperature.8.1.6 Relative humidity.8.1.7 Barometric pressure.8.

24、1.8 Shape and size of probe.8.1.9 Probe speed.8.1.10 Description of probe holding fixture and monitoringdevices.8.1.11 Part number or description of switch, or both, and8.1.12 Date of test.9. Keywords9.1 displacement; membrane switch; switch sensitivity;switch tease; travelASTM International takes n

25、o position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own respon

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27、to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the ad

28、dress shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F 1997 99 (2005)3