1、Designation: F 2072 01 (Reapproved 2007)Standard Practice forHosedown of a Membrane Switch1This standard is issued under the fixed designation F 2072; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber 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 establishes procedures for the hosedown ofa membrane switch to verify adequate protection from ingressof water from a high-
3、volume water spray.1.2 This practice can also be used to verify the ability of amembrane switch or graphics layer to act as a liquid seal for afinished product.1.3 Additional test methods or practices can be incorporatedto investigate specific results or capabilities.1.4 This practice is a modificat
4、ion of NEMA PublicationNumber 250-1991 Section 6.7 which is a test for hosedown ofa finished product housing.2. Referenced Documents2.1 NEMA Publication 250-199123. Terminology3.1 Definitions:3.1.1 membrane switch, na momentary switching devicein which at least one contact is on, or made of, a flexi
5、blesubstrate.3.1.2 specified resistance, nmaximum allowable resis-tance as measured between two terminations whose internalswitch contacts, when held closed, complete a circuit.4. Significance and Use4.1 The presence of water inside a membrane switch canaffect its mechanical operation or electrical
6、functionality, orboth.4.2 This practice establishes a procedure to verify the abilityof a membrane switch to resist the entry of liquid into itself ora finished product, or both. It is useful in identifying designdeficiencies.4.3 Hosedown testing may be destructive, therefore anysamples tested shoul
7、d be considered unfit for future use.5. Interferences5.1 External VentingAny deliberate external venting ofthe switch will allow liquid to enter.5.2 Atmospheric PressureSignificant changes in atmo-spheric pressure during the test or at different facilities mayalter the time in which leakage might oc
8、cur.5.3 Duration of TestLonger exposure time increases thepossibility of leakage.5.4 Dye ColoringChoose a dye coloring that will notchemically attack the materials.6. Apparatus6.1 Water Supply, capable of delivering a stream of water ata rate of at least 65 gal/min through a 1 in. (25 mm) internaldi
9、ameter nozzle for the specified duration,6.2 An appropriate device or fixture to hold the switch in afixed position,6.3 Any additional equipment as required by other testmethods employed, and6.4 Nozzle with 1 in. (25 mm) internal diameter.7. Test Specimen7.1 The test specimen will be a membrane swit
10、ch with orwithout graphics laminated to a rigid material or the finalintended mounting configuration (using a clear material willfacilitate visual inspection).8. Conditioning8.1 Condition specimens by exposure to ambient conditionsfor 72 h prior to hosedown to allow full cure of adhesives.9. Procedu
11、re9.1 Pre-Test Setup:9.1.1 Fixture Unit Under Test (UUT) as specified.9.2 In-Process Test:9.2.1 Test switch for proper function if required.9.2.2 Direct water flow at test specimen at all angles ofpotential water entry such as seams, joints, external operatingmechanisms, etc. from a distance of 10 t
12、o 12 ft (3.0 to 3.5 m)for a total of 5 min or as specified.9.2.3 Test switch for proper function if required.1This 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 Feb. 1, 2007
13、. Published March 2007. Originallyapproved in 2000. Last previous edition approved in 2001 as F 207201.2National Electrical Manufacturers Association (NEMA), 1300 North 17thStreet, Suite 1847, Rosslyn, VA 22209.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
14、19428-2959, United States.9.2.4 Perform visual inspection to determine if liquid haspenetrated the UUT.10. Report10.1 Report the following information:10.1.1 Duration of test,10.1.2 Physical/Aesthetic changes, and10.1.3 Functional test data, if required.11. Keywords11.1 hose down; membrane switch; w
15、ater sprayASTM 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 of any such patent rights, and the riskof infringement of such r
16、ights, 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 not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for addition
17、al standardsand should be addressed 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 AS
18、TM 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,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 2072 01 (2007)2
