1、Designation:F218702(Reapproved 2011)Standard Test Method forDetermining the Effect of Random Frequency Vibration on aMembrane Switch or Membrane Switch Assembly1This standard is issued under the fixed designation F2187;the number immediately following the designation indicates the year oforiginal ad
2、option 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 establishes procedures for determiningthe effect of random v
3、ibration,within the specified frequencyrange,on switch contacts,mounting hardware,adhered com-ponent parts,solder or heat stakes,tactile devices,and cable orribbon interconnects associated with a membrane switch ormembrane switch assembly.1.2 The values stated in SI units are to be regarded asstanda
4、rd.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-bi
5、lity of regulatory limitations prior to use.2.Terminology2.1 Definitions:2.1.1 contact closurethe event at which a specified resis-tance is achieved on a membrane switch.2.1.2 membrane switcha momentary switching device inwhich at least one contact is on,or made of,a flexiblesubstrate.2.1.3 specifie
6、d resistancemaximum allowable circuit re-sistance as measured between two test points whose internalcontacts,when held closed,complete a circuit.2.1.4 test pointstwo pre-selected conductive points in acircuit loop,possibly including a switch.3.Significance and Use3.1 Vibration encountered in the fie
7、ld is usually random innature and this test can be used to determine the effects ofrandom excitation on the membrane switch.3.2 Random vibration can cause mechanical fatigue andfailure by switch components either loosening or otherwisechanging over time.3.3 Experience has shown that this test will e
8、xpose potentialfailures associated with the electronic components of a mem-brane switch,where tests of lower levels will not.3.4 This practice can be used to qualify a membrane switchfor aerospace,medical and other applications.3.5 This test is potentially destructive,intended for devicequalificatio
9、n.4.Apparatus4.1 Vibration Fixture,capable of holding the unit under testand subjecting it to the specified random frequency andduration as described in the In-Process Test.4.2 Contact Closure Detection Device,instrumentation ca-pable of resolving a switch opening time of greater than orequal to 1.0
10、 ms.5.Procedure5.1 Pre-Test Setup:5.1.1 Secure membrane switch on vibration test surfacewith appropriate fixturing.5.1.2 Function testing to be specified and performed againafter test completion for comparison.5.1.3 Connect switch detection leads to test points on themembrane switch.5.2 In-Process T
11、est:5.2.1 Subject to a random vibration over the bandwidth of10 to 2000 for a duration of 1 h per each orthogonal axis(totalof 3 h).The break points shall be as follows:NOTE1The tolerance shall be 3db for this test.FrequencyG2/Hz400.0420000.04Overall GRMS8.855.2.2 Visual inspection shall be conducte
12、d after each axis ofvibration.5.2.3 Electrical and functional testing shall be specified bythe qualified engineer and performed at either test completionor between each axis of vibration.1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility
13、of Subcommittee F01.18 on MembraneSwitches.Current edition approved Feb.1,2011.Published March 2011.Originallyapproved in 2002.Last previous edition approved in 2002 as F2187-02.DOI:10.1520/F2187-02R11.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.Uni
14、ted States1 5.2.4 Afailure shall occur if parts show signs of mechanicalfatigue,cracking,excessive rubbing or loosening of the sup-porting hardware.Afailure should also be designated if contactclosure occurs during vibration and or electrical or otherfunctional testing provides unsatisfactory result
15、s.6.Report6.1 Report the following information:6.1.1 Description of vibration equipment used,6.1.2 Description of mounting fixture including drawing,diagrams,and photos as necessary,6.1.3 Functional testing results before and after test,6.1.4 Description of the visual fatigue of any components orhar
16、dware,6.1.5 Contact closure event;when occurred and axis beingtested,6.1.6 Temperature,6.1.7 Relative humidity,6.1.8 Barometric pressure,6.1.9 Part number or description of switch,or both,and6.1.10 Date of test.7.Keywords7.1 contact closure;frequency;membrane switch;vibrationASTM International takes no 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