ASTM F1895-98(2004)
(Practice)Practice for Submersion of a Membrane Switch
Practice for Submersion of a Membrane Switch
SIGNIFICANCE AND USE
The presence of water inside a membrane switch can affect its mechanical operation or electrical functionality, or both. Electrical failure can result as short circuits due to silver migration or exceeding the specified resistance due to oxidation.
This practice establishes a procedure to verify the ability of a membrane switch to resist the entry of liquid in itself or a finished product, or both. It is useful in identifying design deficiencies.
Submersion testing may be destructive, therefore any samples tested should be considered unfit for future use.
SCOPE
1.1 This practice establishes procedures for the submerging of a membrane switch to verify resistance to ingress of a specified liquid.
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 National Electrical Manufacturers Assoc. (NEMA) Publication Number 250-1991 Section 6.10, which is a test for submersion of a finished product housing.
1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation:F1895–98(Reapproved2004)
Practice for
Submersion of a Membrane Switch
This standard is issued under the fixed designation F1895; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Significance and Use
1.1 This practice establishes procedures for the submerging 4.1 The presence of water inside a membrane switch can
of a membrane switch to verify resistance to ingress of a affect its mechanical operation or electrical functionality, or
specified liquid. both. Electrical failure can result as short circuits due to silver
1.2 This practice can also be used to verify the ability of a migration or exceeding the specified resistance due to oxida-
membrane switch or graphics layer to act as a liquid seal for a tion.
finished product. 4.2 This practice establishes a procedure to verify the ability
1.3 Additional test methods or practices can be incorporated of a membrane switch to resist the entry of liquid in itself or a
to investigate specific results or capabilities. finished product, or both. It is useful in identifying design
1.4 This practice is a modification of National Electrical deficiencies.
Manufacturers Assoc. (NEMA) Publication Number 250-1991 4.3 Submersion testing may be destructive, therefore any
Section 6.10, which is a test for submersion of a finished samples tested should be considered unfit for future use.
product housing.
5. Interferences
1.5 The values stated in inch-pound units are to be regarded
5.1 External Venting—any deliberate external venting of the
as the standard. The values given in parentheses are for
information only. switch will allow liquid to enter.
5.2 Atmospheric Pressure—significant changes in atmo-
2. Referenced Documents
spheric pressure during the test or at different facilities may
2.1 National Electrical Manufacturers Assoc.: alter the time in which leakage might occur.
NEMA Publication 250-1991 5.3 Duration of Test—longer submersion time increases the
possibility of leakage.
3. Terminology
5.4 Dye Coloring—chose a dye coloring that will not
3.1 Definitions:
chemical attack the materials.
3.1.1 membrane switch—A momentary switching device in
6. Apparatus
which at least one contact is on, or made of, a flexible
substrate. 6.1 Tub of sufficient size and depth (w/cover) for the entire
3.1.2 specified resistance—maximum allowable resistance switch, including any mounting surface to be submerged by at
as measured between two terminations whose internal switch least 1 in. (25.4 mm) or as specified.
contacts, when held closed, complete a circuit. 6.2 An appropriate device of fixture to hold the switch in a
3.1.3 silver migration—growth of fine crystals between fixed position.
silver conductors of a thick film circuit due to an ionic reaction 6.3 Any additional equipment as required by other test
to the presence of water and an applied dc voltage potential. methods employed.
7. Test Specimen
7.1 The test specimens may be membrane switches with or
This practic
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