ASTM F1663-95(2002)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:F 1663–95 (Reapproved 2002)
Standard Test Method for
Determining the Capacitance of a Membrane Switch
This standard is issued under the fixed designation F 1663; 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 6.1.2 Attach to the capacitance measuring instrument any
necessary leads, probes or connectors required to connect the
1.1 This test method covers the determination of capaci-
membrane switch assembly for measurement. Place test leads
tance(s) of a membrane switch.
as close to test points as possible without physical connection.
2. Terminology
(This will reduce any variations due to lead positioning).
6.1.3 Record the capacitance reading indicated on the in-
2.1 Definitions:
strument to equal capacitance (C) (this is the capacitance of
2.1.1 membrane switch—a momentary switching device in i
the test setup).
which at least one contact is on, or made of, a flexible
6.2 In-Process Test:
substrate.
6.2.1 Connect test leads to the test points.
2.1.2 test points—two preselected mutually insulated loca-
6.2.2 Record the capacitance reading indicated on the in-
tions on switch assembly.
strument to equal total capacitance (C) (this is the total
t
3. Significance and Use
capacitance of the switch and device.
3.1 Capacitance testing is useful for design verification,
7. Calculation
quality control of materials, and workmanship.
7.1 Calculate the capacitance of the switch specimen as
3.2 High capacitance may interfere with the reliable perfor-
follows:
mance of interface electronics.
3.3 Specific areas of testing are, but not limited to:
Capacitance ~C ! 5 C 2 C
s t i
3.3.1 Conductor/dielectric/conductor crossing point,
8. Report
3.3.2 Close proximity of conductors, and
3.3.3 Any other conductive surface such as shielding or 8.1 Report the following information:
metal backing panel.
8.1.1 Temperature,
8.1.2 Humidity,
4. Interferences
8.1.3 Barometric pressure,
4.1 The following parameters may affect the results of this
8.1.4 Date of test,
test:
8.1.5 Part number or description of the switch specimen, or
4.1.1 Humidity,
both,
4.1.2 Contamination,
8.1.6 Conductive p
...