ASTM F1661-96(2002)

Standard Test Method for Determining the Contact Bounce Time of a Membrane Switch

SIGNIFICANCE AND USE
Contact bounce time is essential to manufacturers and users when designing interface circuitry because it specifies the time delay necessary in the decoder circuitry to avoid any false signals caused by contact bounce. Allowing for time delay makes the switch operation considerably more reliable.
SCOPE
1.1 This test method covers the determination of the contact bounce time 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.

General Information

• Status: Historical
• Publication Date: 09-Dec-1996
• ICS: 29.120.40 - Switches
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.18 - Printed Electronics

Relations

• Replaces: ASTM F1661-96 - Standard Test Method for Determining the Contact Bounce Time of a Membrane Switch
• Effective Date: 10-Dec-1996
• Replaced By: ASTM F1661-08 - Standard Test Method for Determining the Contact Bounce Time of a Membrane Switch
• Effective Date: 01-Nov-2008
• Referred By: ASTM F1596-15 - Standard Test Method for Exposure of a Membrane Switch or Printed Electronic Device to Temperature and Relative Humidity (Withdrawn 2024)
• Effective Date: 10-Dec-1996

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:F 1661–96 (Reapproved 2002)
Standard Test Method for
Determining the Contact Bounce Time of a Membrane
Switch
This standard is issued under the fixed designation F 1661; 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 contact
bounce time 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 appro-
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D 2240 Test Method for Rubber Property—Durometer
FIG. 1 Contact Bounce on Switch Break
Hardness
3.1.8 specified resistance, R —maximum allowable resis-
3. Terminology
S
tance measured between two terminations whose internal
3.1 Definitions:
switch contacts, when held closed, complete a circuit.
3.1.1 contact bounce—intermittent contact opening and
3.1.9 specified upper transition voltage, SUTV—minimum
contact closure that may occur after switch operation.
allowable UTV.
3.1.2 contact bounce time (break), T —the time period
CBB
3.1.10 upper transition voltage, UTV—the voltage at which
measured from the first instant V is equal to the SLTV until
M
the switched logic device transitions to an 88on” state.
the first instant it again falls below the SLTV after the last
3.1.11 voltage, measured, V —voltage measured across
M
instant it rises above the SUTV. If V does not rise above
M
load Resistor (R ) by the oscilloscope and measured on it’s
L
SUTV during the time interval, T = 0, (see Fig. 1).
CBB
screen or voltage measured across the switch under test when
3.1.3 contact bounce time (make), T —the time period
CBM
a contact bounce measuring device is used.
measured from the first instant V is equal to the SUTV until
M
the first instant it again rises above the SUTV after the last
4. Significance and Use
instant it falls below the SLTV. If V does not fall below SLTV
M
4.1 Contact bounce time is essential to manufacturers and
during the time interval, T = 0, (see Fig. 2).
CBM
userswhendesigninginterfacecircuitrybecauseit specifies the
3.1.4 lower transition voltage, LTV—the voltage at which
time delay necessary in the decoder circuitry to avoid any false
the switched logic device transitions to an “off” state.
3.1.5 membrane switch—a momentary switching device in
which at least one contact is on, or made of, a flexible
substrate.
3.1.6 resistor, load, R —load resistance in series with
L
switch under test.
3.1.7 specified lower transition voltage, SLTV—minimum
allowable LTV.
This test method is under the jurisdiction of ASTM Committee F01 on
Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane
Switches.
Current edition approved Dec. 10, 1996. Published February 1997. Originally
published as F 1661 – 95. Last previous edition F 1661 – 95.
Annual Book of ASTM Standards, Vol 09.01. FIG. 2 Contact Bounce on Switch Make
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F 1661–96 (2002)
signals caused by contact bounce. Allowing for time delay
makes the switch operation considerably more reliable.
5. Interference
5.1 The following parameters may affect the results of this
test:
5.1.1 If a human finger is used in place of a mechanical
probe the results are more varied and larger sample sizes
should be used, and
5.1.2 Mechanical probe materials (hardness) and speed will
affect results.
FIG. 4 Test Probe Option
6. Apparatus
6.1 Test Probe, built to either of the configuration shown in
Fig. 3 and Fig. 4 are acceptable but must be made of an inert
elastomeric material with a hardness number equivalent to
A/45 6 5 as measured in accordance with Test Method
D 2240.Test probes that do not meet the above criteria must be
fully specified and recorded.
6.2 Test Surface—flat, smooth, unyielding, and
...