ASTM B615-79(2022)

Standard Practice for Measuring Electrical Contact Noise in Sliding Electrical Contacts

SIGNIFICANCE AND USE
3.1 Resistance or voltage values alone do not provide sufficient detail for an engineering evaluation of contact noise. This practice lists the test conditions that should be reported with noise measurements and indicates some conditions (open circuit voltages, currents, etc.) that have been used for quality control and research studies. The use of these practices should provide sufficient detail for an engineering interpretation of the noise data and allow the tests to be repeated by another laboratory.
SCOPE
1.1 This practice describes the practices and factors considered to be most important in the measurement of electrical contact noise of sliding contacts.  
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 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.  
1.3 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

• Status: Published
• Publication Date: 31-Mar-2022
• ICS: 29.160.10 - Components for rotating machines
• Technical Committee: B02 - Nonferrous Metals and Alloys
• Drafting Committee: B02.05 - Precious Metals and Electrical Contact Materials and Test Methods

Overview

ASTM B615-79(2022): Standard Practice for Measuring Electrical Contact Noise in Sliding Electrical Contacts provides comprehensive practices and guidelines for the evaluation of electrical noise in sliding contact systems, such as those found in electromechanical devices. Developed by ASTM International, this standard is widely recognized for ensuring consistent, repeatable measurement and interpretation of contact noise data. The standard is essential for professionals concerned with the quality, reliability, and research-focused diagnostics of electrical contacts used in sliding applications.

Electrical contact noise, as defined in this standard, refers to the minute voltage fluctuations that occur at the interface of two electrical contacts when they are in motion relative to each other. Proper measurement and reporting of this contact noise are crucial for a thorough engineering evaluation and to ensure optimal device performance, particularly in environments where low noise levels are critical.

Key Topics

• Test Types: ASTM B615 specifies two primary categories of contact noise testing:

  • Type I: Qualification and acceptance testing, focusing on device performance in actual or simulated operating conditions.
  • Type II: Diagnostic and research testing, aimed at understanding contact phenomena under varied laboratory parameters.

• Test Conditions: The standard outlines critical electrical, mechanical, and environmental parameters to control or document, including:

  • Electrical current and waveform
  • Source voltage and open-circuit voltage
  • Load impedance
  • Circuit configuration
  • Detector and shielding specifications
  • Surface velocity and wipe rate of contacts
  • Test temperature, lubricant control, and atmospheric conditions

• Measurement Techniques: Methods for detecting and quantifying electrical contact noise, such as:

  • Peak-to-peak noise using oscilloscopes or optical recorders
  • Root mean square (RMS) values with specialized voltmeters
  • Pulse detection, spectrum analysis, and other advanced diagnostic techniques

• Reporting Requirements: The standard details necessary elements for reporting, including test type, conditions, technique, measured values, and baseline noise data.

Applications

ASTM B615-79(2022) is applicable across industries where sliding electrical contacts are fundamental to device functionality, reliability, or signal integrity. Key areas of application include:

• Electromechanical Device Manufacturing: Used in the qualification and quality control of slip rings, potentiometers, switches, and relays, ensuring devices meet noise performance criteria.
• Aerospace and Guidance Systems: Vital for devices that demand extremely low electrical contact noise, such as inertial guidance platforms.
• Research and Development: Facilitates investigation into contact tribology and material interactions by providing a basis for repeatable, scientifically-sound noise measurements.
• Maintenance and Diagnostics: Useful in ongoing reliability assessments and predictive maintenance strategies for critical industrial and transportation systems.

By following this standard, organizations can reliably compare test results, identify sources of excess noise, and ensure compliance with industry best practices for electrical contact integrity.

Related Standards

To further support best practices in electrical contact measurement, users may also consider the following related ASTM and international standards:

• ASTM B539 - Standard Test Method for Evaluation of Electrical Contact Materials
• ASTM B667 - Standard Practice for Construction and Use of a Probe for Electrical Contact Resistance Measurements
• IEC 60512-2 - Connectors for Electronic Equipment - Tests and Measurements: Contact Resistance
• ASTM B700 - Standard Specification for Electrodeposited Coatings on Electrical Conductors

These standards, along with ASTM B615-79(2022), contribute to the robust measurement, comparison, and assurance of electrical contact performance in sliding systems, supporting improved product reliability and research outcomes.

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: 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
...