ASTM F2112-01

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: F 2112 – 01
Standard Terminology for
Membrane Switches
This standard is issued under the fixed designation F 2112; 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 isolated test points on a membrane switch.
membrane layer—a flexible dynamic layer which carries one
1.1 This terminology defines terms that are commonly used
or both switch poles the deflection of which is used to short
in the membrane switch industry.
both poles together. The membrane layer is a required
1.2 These definitions are not mutually exclusive.
component of a membrane switch. See Fig. 1.
2. Terminology membrane switch—a momentary switching device in which
at least one contact is on, or made of, a flexible substrate.
actuation force—the maximum force measured prior to or
open circuit resistance—minimum allowable resistance as
including point at which contact closure is achieved on a
measured between two test points that, if lower then, will
membrane switch.
indicate an electrical short.
circuit resistance—electrical resistance as measured between
rigid layer—provides mechanical support for the membrane
two test points whose internal contacts, when held closed,
switch. See Fig. 1.
complete a circuit.
silver migration—a process by which silver, when in contact
conductor resistance—the measured electrical resistance
with insulating materials under electrical potential, is re-
through a circuit loop between two test points.
moved ionically from its original location, and is redeposit
contact bounce—intermittent contact opening and contact
as a metal (silver dendrite) at some other location.
closure that may occur after switch operation.
spacer layer—a material (usually dielectric) sometimes used
contact closure—the event at which a specified resistance is
to maintain a separation between the membrane layer and
achieved on a membrane switch.
static layer of a membrane switch.
contact force—the force at contact closure.
specified circuit resistance—maximum allowable circuit re-
current carrying capacity—the maximum level of electrical
sistance as measured between two terminations whose inter-
current that a circuit can conduct without sustaining damage.
nal contacts, when held closed, complete a circuit.
dielectric withstand voltage—the maximum voltage a dielec-
static layer—a mechanically supported layer which carries
tric can withstand in a membrane switch without a visual
one or both poles of
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