ASTM B854-98(2022)
(Guide)Standard Guide for Measuring Electrical Contact Intermittences
Standard Guide for Measuring Electrical Contact Intermittences
SIGNIFICANCE AND USE
4.1 This guide suggests techniques to evaluate intermittences in a contact pair while it is subjected to simulated or actual environmental stress. Such measurements are a valuable tool in predicting circuit performance under these stress conditions and in diagnosing observed problems in circuit function under such conditions.
4.2 This document is intended to provide some general guidance on the best available practices for detecting, quantifying, characterizing and reporting short duration intermittences in circuits containing electrical contacts. Certain environmental stresses such as mechanical shock, vibration or temperature change may cause intermittences. These measurement procedures include methods applicable to contacts operating under various conditions in testing or in service.
4.3 Practice B615 defines methods for measuring electrical contact noise in sliding electrical contacts. In contrast Guide B854 provides guidance to the various methods for measuring similar phenomena in static contacts.
SCOPE
1.1 The techniques described in this guide apply to electrical circuits that include one or more electrical contacts in devices such as slip rings, separable connectors, electromechanical relays or closed switch contacts. The user should determine applicability for other devices.
1.2 The range of techniques described apply to circuit discontinuities (intermittences) of durations ranging from approximately 10 nanoseconds to several seconds and of sufficient magnitude to cause alteration of the circuit function. Extension of the guide to shorter duration events may be possible with suitable instrumentation. Events of longer duration may be monitored by techniques for dc measurements such as those described in Test Methods B539 or by adaptation of methods described in this guide.
1.3 The techniques described in this guide apply to electrical circuits carrying currents typical of signal circuits. Such currents are generally less than 100 ma. Extension of these techniques to circuits carrying larger currents may be possible, but the user should evaluate applicability first.
1.4 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 become familiar with all hazards including those identified in the appropriate Safety Data Sheet (SDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental practices, and determine the applicability of regulatory limitations prior to use.
1.5 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.
General Information
Relations
Standards Content (Sample)
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: B854 − 98 (Reapproved 2022)
Standard Guide for
Measuring Electrical Contact Intermittences
This standard is issued under the fixed designation B854; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2.1 ASTM Standards:
1.1 The techniques described in this guide apply to electri-
B539 Test Methods for Measuring Resistance of Electrical
cal circuits that include one or more electrical contacts in
Connections (Static Contacts)
devices such as slip rings, separable connectors, electrome-
B542 Terminology Relating to Electrical Contacts and Their
chanical relays or closed switch contacts. The user should
Use
determine applicability for other devices.
B615 Practice for Measuring Electrical Contact Noise in
1.2 The range of techniques described apply to circuit
Sliding Electrical Contacts
discontinuities (intermittences) of durations ranging from ap-
B878 Test Method for Nanosecond Event Detection for
proximately 10 nanoseconds to several seconds and of suffi-
Electrical Contacts and Connectors
cient magnitude to cause alteration of the circuit function.
2.2 Other Documents:
Extension of the guide to shorter duration events may be
IEC Publication 512 Test 2e Contact Disturbance
possible with suitable instrumentation. Events of longer dura-
EIA-364-46 Continuity Test Procedure for Electrical Con-
tion may be monitored by techniques for dc measurements
nectors
such as those described in Test Methods B539 or by adaptation
of methods described in this guide.
3. Terminology
1.3 The techniques described in this guide apply to electri-
3.1 Terms relevant to this guide are defined in Terminology
cal circuits carrying currents typical of signal circuits. Such
B542 except as noted in the following section.
currents are generally less than 100 ma. Extension of these
3.2 Definitions of Terms Specific to This Standard:
techniques to circuits carrying larger currents may be possible,
3.2.1 intermittence, n—a transient increase in the voltage
but the user should evaluate applicability first.
drop across a pair of electrical contacts.
1.4 This standard does not purport to address all of the
4. Significance and Use
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to become familiar
4.1 This guide suggests techniques to evaluate intermit-
with all hazards including those identified in the appropriate
tences in a contact pair while it is subjected to simulated or
Safety Data Sheet (SDS) for this product/material as provided
actual environmental stress. Such measurements are a valuable
by the manufacturer, to establish appropriate safety, health,
tool in predicting circuit performance under these stress
and environmental practices, and determine the applicability
conditions and in diagnosing observed problems in circuit
of regulatory limitations prior to use.
function under such conditions.
1.5 This international standard was developed in accor-
4.2 This document is intended to provide some general
dance with internationally recognized principles on standard-
guidance on the best available practices for detecting,
ization established in the Decision on Principles for the
quantifying, characterizing and reporting short duration inter-
Development of International Standards, Guides and Recom-
mittences in circuits containing electrical contacts. Certain
mendations issued by the World Trade Organization Technical
environmental stresses such as mechanical shock, vibration or
Barriers to Trade (TBT) Committee.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
This guide is under the jurisdiction of ASTM Committee B02 on Nonferrous Standards volume information, refer to the standard’s Document Summary page on
Metals and Alloys and is the direct responsibility of Subcommittee B02.05 on the ASTM website.
Precious Metals and Electrical Contact Materials and Test Methods. Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
Current edition approved April 1, 2022. Published April 2022. Originally 4th Floor, New York, NY 10036, http://www.ansi.org.
approved in 1998. Last previous edition approved in 2016 as B854 – 98 (2016). Available from Electronic Industries Association, 2001 Pennsylvania Ave NW,
DOI: 10.1520/B0854-98R22. Washington D.C. 20006.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B854 − 98 (2022)
temperature change may cause intermittences. These measure-
ment procedures include methods applicable to contacts oper-
ating under various conditions in testing or in service.
4.3 Practice B615 defines methods for measuring electrical
contact noise in sliding electrical contacts. In contrast Guide
B854 provides guidance to the various methods for measuring
similar phenomena in static contacts.
5. Apparatus
5.1 General Comments—The apparatus required varies de-
pending upon the technique selected and the parameters (such
FIG. 1 Schematic Representation of Oscilloscope Method
as duration and magnitude) of the intermittence that the user
wants to detect. In general, the cabling must be capable of
carrying signals of the speed to be detected in the study, and
must be isolated from sources of noise that may cause false
6.1.2 Is it necessary to monitor more than one contact
indications.
simultaneously? If so, is it acceptable to connect the contacts in
5.2 Special Precautions for Measurements Involving Events
series? If contacts cannot be connected in series, how many
Less than 1 Microsecond in Duration—Detection of events of
contacts must be measured simultaneously?
duration less than 1 microsecond will require special attention
6.2 Test results should be reported in a format appropriate
to the wiring of the detection circuits and instrumentation.
for the application and consistent with the format supplied by
Such attention may include using coaxial cable, shielding the
the test instrument.
apparatus from interferences and minimizing cable lengths.
6.3 Oscilloscope—In this method, an oscilloscope is wired
5.3 Specific Apparatus—The apparatus required will vary
to monitor the potential across the contact(s) of interest while
depending upon the measurement method selected and the
a signal is passed through the contacts. Standards such as IEC
environmental stresses imposed during the test.
Publication 512, Test 2e or EIA-364-46 are often implemented
using this method. Practice B615 provides a specific circuit
6. Procedure
that uses this method. Examples of the use of this method are
6.1 General Comments—The following sections describe,
shown in the reference by Currence and Rhoades.
in general terms, several methods that have been used to detect
6.3.1 Fig. 1 shows a schematic representation of an example
or measure contact intermittences. The user should select an
of how this method may be implemented. In selecting an
appropriate method and adapt it as required. Table 1 presents a
oscilloscope, choose a model with response time fast enough to
comparison of the attributes of the various methods. The
observe events of the duration of interest in the study. The user
following list covers questions that the user should answer
may find it convenient to use an oscilloscope capable of storing
before selecting a test method.
and printing results.
6.1.1 What is the definition of an intermittence in the
intended application? For example, what resistance change
over what time interval constitutes an intermittence, or what
Currence, R. and Rhoades, W., “Predicting, Modeling and Measuring Transient
error occurs if the contact resistance changes, or what other
Resistance Changes of Degraded Electrical Contacts,” Electrical Contacts, Proceed-
definition is appropriate for the intended purpose of the test
ings of the 29th Meeting of the Holm Conference on Electrical Contacts, Illinois
results? Institute of Technology, p. 81, 1983.
TABLE 1 Comparison of Methods of Monitoring Electrical Contact Intermittences
Typical Number Typical Event Possible
Method
of Channels Characterization Advantages
Oscilloscope 1, 2 or 4 ΔV vs time Detailed characterization of each event
Custom Circuitry 1 per circuit Presence or absence of one or more events during a Ability to closely model actual circuit conditions,
preselected monitoring interval, such events defined allows use of various technologies in the transmitting
as above a preselected threshold of ΔR and duration, and receiving devices
the number of events during the interval may or may
not be recorded.
Event Detector 1 to 64 Presence or absence of one or more events during a Multichannel capability, selection of thresholds
...
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