ASTM F1661-09(2015)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F1661 − 09 (Reapproved 2015)
Standard Test Method for
Determining the Contact Bounce Time of a Membrane
Switch
This standard is issued under the fixed designation F1661; 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 it constantly remains above the SUTV after the last instant it
falls below the SLTV. If V does not fall below SLTV during
M
1.1 This test method covers the determination of the contact
the time interval, T = 0, (see Fig. 2).
CBM
bounce time of a membrane switch.
3.1.4 lower transition voltage, LTV—the voltage at which
1.2 The values stated in SI units are to be regarded as
the switched logic device transitions to an “off” state.
standard. No other units of measurement are included in this
3.1.5 membrane switch—a momentary switching device in
standard.
which at least one contact is on, or made of, a flexible
1.3 This standard does not purport to address all of the
substrate.
safety concerns, if any, associated with its use. It is the
3.1.6 resistor, load, R —loadresistanceinserieswithswitch
responsibility of the user of this standard to establish appro- L
under test.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
3.1.7 specified lower transition voltage, SLTV— minimum
allowable LTV.
2. Referenced Documents
3.1.8 specified upper transition voltage, SUTV— minimum
2.1 ASTM Standards:
allowable UTV.
D2240 Test Method for Rubber Property—Durometer Hard-
3.1.9 upper transition voltage, UTV—the voltage at which
ness
the switched logic device transitions to an ''on” state.
F2592 Test Method for Measuring the Force-Displacement
3.1.10 voltage, measured, V —voltage measured across
of a Membrane Switch M
load Resistor (R ) by the oscilloscope and measured on it’s
F1680 Test Method for Determining Circuit Resistance of a L
screen or voltage measured across the switch under test when
Membrane Switch
a contact bounce measuring device is used.
3. Terminology
4. Significance and Use
3.1 Definitions:
4.1 Contact bounce time is essential to manufacturers and
3.1.1 contact bounce—intermittent contact opening and
userswhendesigninginterfacecircuitrybecauseitspecifiesthe
contact closure that may occur after switch operation.
time delay necessary in the decoder circuitry to avoid any false
3.1.2 contact bounce time (break), T —the time period
CBB
signals caused by contact bounce. Allowing for time delay
measured from the first instant V is equal to the SUTV until
M
makes the switch operation considerably more reliable.
it constantly remains below the SLTV after the last instant it
rises above the SUTV. If V does not rise above SUTV during
M 5. Interference
the time interval, T = 0, (see Fig. 1).
CBB
5.1 The following parameters may affect the results of this
3.1.3 contact bounce time (make), T —the time period
CBM
test:
measured from the first instant V is equal to the SLTV until
M
5.1.1 Mechanical probe materials (hardness) and speed will
affect results.
This test method is under the jurisdiction of ASTM Committee F01 on
6. Apparatus
Electronics and is the direct responsibility of Subcommittee F01.18 on Printed
Electronics.
6.1 Test Probe, built to either of the configuration shown in
Current edition approved June 1, 2015. Published August 2015. Originally
Fig. 3 and Fig. 4 are acceptable but must be made of an inert
approved in 1995. Last previous edition approved in 2009 as F1661 – 09. DOI:
10.1520/F1661-09R15.
elastomeric material with a hardness number equivalent to
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
A/45 6 5 as measured in accordance withTest Method D2240.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Test probes that do not meet the above criteria must be fully
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. specified and recorded.
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F1661 − 09 (2015)
FIG. 4 Test Probe Option
FIG. 1 Contact Bounce on Switch Break
7.1.1 Determine Fmax or Fc (whichever is greater) per Test
Method F2592.
7.1.2 Determin
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