ASTM F2072-00

Standard Practice for Hosedown of a Membrane Switch

SCOPE
1.1 This practice establishes procedures for the hosedown of a membrane switch to verify adequate protection from ingress of water from a high-volume water spray.
1.2 This practice can also be used to verify the ability of a membrane switch or graphics layer to act as a liquid seal for a finished product.
1.3 Additional test methods or practices can be incorporated to investigate specific results or capabilities.
1.4 This practice is a modification of NEMA Publication Number 250-1991 Section 6.7 which is a test for hosedown of a finished product housing.

General Information

• Status: Historical
• Publication Date: 09-Jun-2001
• ICS: 31.220.20 - Switches
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.18 - Printed Electronics

Relations

• Replaced By: ASTM F2072-01 - Standard Practice for Hosedown of a Membrane Switch
• Effective Date: 10-Jun-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: F 2072 – 00
Standard Practice for
Hosedown of a Membrane Switch
This standard is issued under the fixed designation F 2072; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 5. Interferences
1.1 This practice establishes procedures for the hosedown of 5.1 External Venting—Any deliberate external venting of
a membrane switch to verify resistance to ingress of a the switch will allow liquid to enter.
high-volume water spray. 5.2 Atmospheric Pressure—Significant changes in atmo-
1.2 This practice can also be used to verify the ability of a spheric pressure during the test or at different facilities may
membrane switch or graphics layer to act as a liquid seal for a alter the time in which leakage might occur.
finished product. 5.3 Duration of Test—Longer exposure time increases the
1.3 Additional test methods or practices can be incorporated possibility of leakage.
to investigate specific results or capabilities. 5.4 Dye Coloring—Choose a dye coloring that will not
1.4 This practice is a modification of NEMA Publication chemically attack the materials.
Number 250-1991 Section 6.7 which is a test for hosedown of
6. Apparatus
a finished product housing.
6.1 Water Supply, capable of delivering 65 gal/min through
2. Referenced Documents
a 1 in. nozzle for the specified duration,
2.1 NEMA Publication 250-1991 6.2 An appropriate device or fixture to hold the switch in a
fixed position,
3. Terminology
6.3 Any additional equipment as required by other test
3.1 Definitions:
methods employed, and
3.1.1 membrane switch, n—a momentary switching device 6.4 Water Hose and 1 in. Nozzle.
in which at least one contact is on, or made of, a flexible
7. Test Specimen
substrate.
3.1.2 silver migration, n—the growth of fine crystals be- 7.1 The test specimen will be a membrane switch with or
tween silver conductors of a thick film circuit due to an ionic without graphics laminated to a rigid material or the final
reaction to the presence of water and an applied dc voltage intended mounting configuration (using a clear material will
potential. facilitate visual inspection).
3.1.3 specified resistance, n—maximum allowable resis-
8. Conditioning
tance as measured between two terminations whose internal
8.1 Condition specimens by exposure to ambient conditions
switch contacts, when held closed, complete a circuit.
for 72 h prior to hosedown to allow full cure of adhesives.
4. Significance and Use
9. Procedure
4.1 The presence of water inside a m
...