ASTM B615-79(2022)

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: B615 − 79 (Reapproved 2022)
Standard Practice for
Measuring Electrical Contact Noise in Sliding Electrical
Contacts
This standard is issued under the fixed designation B615; 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 3. Significance and Use
3.1 Resistance or voltage values alone do not provide
1.1 This practice describes the practices and factors consid-
sufficient detail for an engineering evaluation of contact noise.
ered to be most important in the measurement of electrical
This practice lists the test conditions that should be reported
contact noise of sliding contacts.
with noise measurements and indicates some conditions (open
1.2 This standard does not purport to address all of the
circuit voltages, currents, etc.) that have been used for quality
safety concerns, if any, associated with its use. It is the
control and research studies. The use of these practices should
responsibility of the user of this standard to become familiar
provide sufficient detail for an engineering interpretation of the
with all hazards including those identified in the appropriate
noise data and allow the tests to be repeated by another
Safety Data Sheet (SDS) for this product/material as provided
laboratory.
by the manufacturer, to establish appropriate safety, health,
and environmental practices, and determine the applicability 4. Types of Testing
of regulatory limitations prior to use.
4.1 Type I—Qualification and acceptance testing of electro-
1.3 This international standard was developed in accor-
mechanical devices when low electrical contact noise is
dance with internationally recognized principles on standard-
important for proper functioning.
ization established in the Decision on Principles for the
4.1.1 Electrical and mechanical parameters should closely
Development of International Standards, Guides and Recom-
simulate the end use of the device.
mendations issued by the World Trade Organization Technical
4.1.2 Since the procedure is used as a method of quality
Barriers to Trade (TBT) Committee.
control, the test parameters must be duplicated each time the
test is conducted.
2. Terminology
4.2 Type II—Measurement of contact voltage variation as a
2.1 Definitions: method of studying tribological phenomena.
4.2.1 Tests are designed with specific diagnostic or research
2.1.1 contact noise, n—the varying voltage across a pair of
goals.
electric contacts due to conditions at their interface. It is to be
4.2.2 Electrical and mechanical parameters are based on
distinguished from the variation of signal due to its transmis-
considerations of basic contact physics and not the engineering
sion through electrical conductors (that is, induced voltages
requirements of the device. Selected parameters may be varied
due to adjacent sources). It is also to be distinguished from
as part of the test. For example, rotational rate of a slip ring
acoustic noise which may be generated by the contact action.
may be varied to determine the surface velocity at which
2.1.1.1 Discussion—Stepwise change of resistance of a
hydrodynamic lift becomes important.
wirewound potentiometer due to the definite resistance of a
single turn is not electrical contact noise.
5. Test Conditions
2.1.2 switching or edge noise, n—the electrical contact
5.1 The following test conditions should be controlled or
noise occurring during the period of transition from conduction
known to enable adequate evaluation of test results:
to non-conduction (or vice versa) of a switching device.
5.1.1 Electrical Parameters:
5.1.1.1 Current—Contact current and waveform should be
specified. The limitations of the instrument(s) being used to
measure the noise and adequacy of shielding from extraneous
This practice is under the jurisdiction of ASTM Committee B02 on Nonferrous
Metals and Alloys and is the direct responsibility of Subcommittee B02.05 on
noise sources must be considered when current level is chosen.
Precious Metals and Electrical Contact Materials and Test Methods.
Type I tests may be made either at current levels chosen to
Current edition approved April 1, 2022. Published April 2022. Originally
simulate those required in actual use or may be at higher
approved in 1979. Last previous edition approved in 2017 as B615 – 79 (2017).
DOI: 10.1520/B0615-79R22. current levels in order to enhance test sensitivity provided any
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B615 − 79 (2022)
such higher current magnitude shall be agreed upon between 5.1.2.3 Special Conditions—Additional description may be
the device user and producer (Note 1). necessary to define the mode of operation completely (for
5.1.1.2 Source Voltage—The maximum open-circuit voltage example, amplitude and frequency of oscillation, duty cycle,
(to the contacts) and the impedance of the source should be reversal of direction).
specified. In Type I tests, the open-circuit voltage levels chosen
5.1.3 Environmental Conditions:
should simulate those required in actual use and may be at
5.1.3.1 Temperature of Test—Temperature should be speci-
more than one level if representative of the end use (Note 1).
fied and held within specific limits.
In Type II tests, any voltage levels may be used depending on
5.1.3.2 Lubrication—Lubrication of the contacts should be
the objectives of the studies being made (Note 2).
held
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