1、Designation: F 1596 00 (Reapproved 2005)Standard Practice forExposure of Membrane Switches to Temperature andRelative Humidity1This standard is issued under the fixed designation F 1596; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, 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 practice covers a procedure for temperature andhumidity cycling of membrane switches.1.2 This pr
3、actice is designed to determine changes inducedby temperature and humidity.1.3 This practice is not intended to be a thermal shockprocedure; a gradual ramp rate between conditions is required.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It
4、 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. Terminology2.1 Definition:2.1.1 membrane switcha momentary switching device inwhich at least one contact is on, or made
5、of, a flexiblesubstrate.3. Significance and Use3.1 Changes in temperature and humidity during shipping,storage or use can affect the visual appearance, mechanicalintegrity, or electrical functionality of switches. This practicesimulates three different environments to which membraneswitches may be e
6、xposed.3.2 The three industry-recognized switch categories basedon performance levels are Level 1, Level 2, and Level 3 (seesection 7.1).3.3 Additionally, there may be custom requirements thatvary by application, therefore, these requirements can bedetermined by customer and vendor agreement and be
7、estab-lished as a Level 4.3.4 This practice defines the duration of a single cycle.Multiple cycles may be appropriate depending on the require-ments of the application.4. Apparatus4.1 Closed system, with temperature and humidity control.24.2 The formation of condensation during rising tempera-ture c
8、ycles is acceptable; the formation of ice during lowtemperature cycling is not acceptable.5. Test Specimens5.1 The specimens shall be finished switches as deliveredand mounted to an actual or agreed upon substrate.6. Conditioning6.1 Condition all specimens for 72 h at 20 to 25C (68 to77F) and 20 to
9、80 % relative humidity (RH) immediately priorto exposure, or prior to temperature and humidity cycling. Thisis to enable the specimens to stabilize.7. Procedure7.1 Subject the preconditioned specimens to the exposuretest cycle as illustrated in Table 1.7.2 Return to room temperature and prepare for
10、evaluation.8. Keywords8.1 membrane switch; relative humidity (RH); temperature1This practice is under the jurisdiction of ASTM Committee F01 on Electronicsand is the direct responsibility of Subcommittee F01.18 on Membrane Switches.Current edition approved May 1, 2005. Published June 2005. Originall
11、yapproved in 1995. Last previous edition approved in 2000 as F 159600.2A closed system such as a Tenney T3ORC, Despatch EC 619, or Espec EMX,available from Tenney, Inc., Union, NJ 07083; Despatch Industries, Minneapolis,MN 55440-1320; ESPEC Corp., Grand Rapids, MI 49509, have been foundsatisfactory
12、for this purpose.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard
13、 are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif n
14、ot revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which
15、 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 address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,Uni
16、ted 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).TABLE 1 Exposure Test CycleLevel 1 40C (40F) to 8
17、5C(185F)Level 2 25C (13F) to 70C(158F)72 h at 85C (185F)Adry heat 72 h at 70C (158F)A24 h at 38C (100F)Aand 95 % RHB24 h at 38C (100F)Aand 95 % RHB8 h at 40C (40F) 8 h at 25C (13F)A40 h at 85C (185F)Adry heat 40 h at 70C (158F)A24 h at 38C (100F)Aand 95 % RHB24 h at 38C (100F)Aand 95 % RHB72 h at 40
18、C (40F)Adry heat 72 h at 25C (13F)ALevel 3 10C (14F) to 55C (131F) Level 4 (Custom Requirement)72 h at 55C (131F)ASee 3.324 h at 38C (100F)Aand 95 % RHA8 h at 10C (14F)A40 h at 55C (131F)A24 h at 38C (100F)Aand 95 % RHA72 h at 10C (14F)AA(62C 6 3.6F and 66.0 % RH).BPlace these samples in a rack at a 45 angle to allow condensate to drain from samples and arrange to allow adequate air flow between samples.F 1596 00 (2005)2
