1、Designation:F286611Standard Test Method forFlammability of a Membrane Switch in Defined Assembly1This standard is issued under the fixed designation F2866;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A nu
2、mber 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 covers the determination of the flam-mability characteristics of a membrane switch.1.2 This test method defines the MSB rati
3、ng of a membraneswitch.Each character of the MSB rating represents a discretecharacteristic of a membrane switch performance under de-structive thermal loading.1.3 This test procedure will be destructive,but shouldprovide an insight into the relative performance flame-resistance characteristics of d
4、iffering designs or assemblies,orboth.1.4 This test method will focus on the use of convectivecontact(burner flame)method for ignition,though othermethods of ignition are available.1.5 This test method is designed to determine if the mem-brane switch assembly will add(or detract)from the flamepropag
5、ation from an exterior flame/fire source.1.6 If this test is intended to be used for an internalflammability source then set up the unit under test(UUT)appropriately and note it in the test scope and results.1.7 This standard does not purport to address all of thesafety concerns,if any,associated wi
6、th 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:2E906 Test Method for Heat and Visible Smoke ReleaseRates for Materia
7、ls and Products Using a ThermopileMethod3.Terminology3.1 Definitions:3.1.1 burn damagepercentage of the UUT that is damageddue to burn test.This is a visiual observation.3.1.2 flame propagationrefers to patterns in the flamefront that are examined(for example,uniform rate of advance,spotty ignition
8、or charring,etc.).These observations arequalitative and should be noted in the data field.3.1.3 flame spread rate(FSR)the rate at which a flamefront travels along the surfaces of tested materials/assemblies,typically measured in mm/s or in./min.3.1.4 flame target arearefers to the normalized target
9、areaof a UUT that will be used for ignition location.Any variationsshould be noted.3.1.5 flame time(Ftime)or flame enduranceamount oftime,usually in seconds,that a self-sustaining flame willendure after removal of initial ignition source before flame onUUT is extinguished.3.1.6 flame time of drippin
10、gs(Ftime,drip)amount of timethat burning drippings,if any,remain burning.Typicallymeasured in seconds.3.1.7 gauze ignitionthis is a verification that UUT ignitesthe gauze.3.1.8 ignition sourcethe source that provides the heat-fluxto begin the flammability test.This test method will recom-mend a conv
11、ective flame for the ignition source,however,careshould be taken that any comparative tests should use the samemethod of ignition.3.1.9 mass-loss(mloss)the mass from a test specimen itlost to smoke,vaporization and char debris carried away orfallen away,or both,during the flammability test cycle.Typ
12、ically measured in grams(average).3.1.10 membrane switch assemblythe membrane switchshould not be tested in its unmounted state.The switch sampleshould be mounted onto the final end-use enclosure,panel,bezel,or agreed upon material.3.1.10.1 DiscussionAssembly Specimen:This test methodis trying to pr
13、ovide a practical world analog for the resultsherein obtained.As a result,the unit under test(UUT)must inthe final mounted condition.The test is able to show flame-resistance in the final assembly as it interacts with themembrane switchs construction.1This test method is under the jurisdiction of AS
14、TM Committee F01 onElectronics and is the direct responsibility of Subcommittee F01.18 on MembraneSwitches.Current edition approved July 1,2011.Published August 2011.Originallyapproved in 2010.Last previous edition approved in 2010 as F2866-10.DOI:10.1520/F2866-11.2For referenced ASTM standards,visi
15、t 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
16、 States1 3.1.11 MSBrating to quantify the burn characteristics of amembrane switch.Each character of the MSB rating representsa discrete characteristic of a membrane switch performanceunder destructive thermal loading.(see Table 1.)3.1.12 time-to-ignition(tign)the time to ignite UUT underthermal loading(by any ignition source selected)with aself-standing flame front on the UUT(flame on the testspecimen moving away from the thermal load source).Themethod for ignition(source)can be conductive cont
