ASTM F1680-07

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:F 1680–07
Standard Test Method for
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Determining Circuit Resistance of a Membrane Switch
This standard is issued under the fixed designation F 1680; 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
1.1 This test method covers the determination of the circuit resistance of a membrane switch.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
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2.1 ASTM Standards:
F 2592 Test Method for Measuring the Force-Displacement of a Membrane Switch
3. Terminology
3.1 Definitions:
3.1.1 circuit resistance—electrical resistance as measured between two test points whose internal contacts, when held closed,
complete a circuit.
3.1.2 membrane switch—a momentary switching device in which at least one contact is on, or made of, a flexible substrate.
3.1.3 test points—two preselected conductive points in a circuit loop, possibly including a switch.
4. Significance and Use
4.1 Resistance is useful to manufacturers and users when designing membrane switch interface circuitry.
5. Apparatus
5.1 Test Probe, as defined in Test Method F 2592.
5.2 Test Surface to be flat, smooth, unyielding and larger than switch under test.
5.3 Device, to hold test probe securely and provide perpendicular movement into and away from switch under test.
5.4 Resistance Measuring Device , (for example, ohm meter).The device should not apply a voltage outside the operating range
of the switch contacts.
5.5 Suitable Device, to apply a controlled and measurable force on the test probe.
6. Procedure
6.1 Pre-Test Setup:
6.1.1 Precondition switch until approximation of steady state condition is achieved. (Note this will typically occur between 5
to 25 cycles, and it is recommended that the instrument and test probe be used when practical.)
6.1.2 Secure switch on test surface so that the unit under test can be removed and replaced in the same position after subsequent
operations (probe contact position within 0.010 in. of its original position on the switch).
6.1.3 Position test probe over desired are of switch.
6.1.4 Lower probe until tip is just above top surface of switch without touching.
6.1.5 Connect switch terminals to resistance measuring device.
6.2 In-Process Test:
6.2.1 Slowly de
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