ASTM B794-97(2003)
(Test Method)Standard Test Method for Durability Wear Testing of Separable Electrical Connector Systems Using Electrical Resistance Measurements
Standard Test Method for Durability Wear Testing of Separable Electrical Connector Systems Using Electrical Resistance Measurements
SCOPE
1.1 This test method covers the effects of repeated insertion and withdrawal of separable electrical connectors which are harmful to the electrical performance of the connector.
1.2 This test method is limited to electrical connectors designed for use in applications where the current through any one connection in the connector does not exceed 5 A, and where the connector may be separated a number of times during the life of the connector.
1.3 This test method is limited to electrical connectors intended for use in air ambients where the operating temperature is less than 65°C.
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 Material Safety Data Sheet for this product/material as provided by the manufacturer, to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use.
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Designation:B794–97(Reapproved2003)
Standard Test Method for
Durability Wear Testing of Separable Electrical Connector
Systems Using Electrical Resistance Measurements
This standard is issued under the fixed designation B 794; 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 particular connector under test, and the resistances of these
connectors are measured again. The connectors in the other
1.1 This test method covers the effects of repeated insertion
group are not disturbed. All samples are subjected to an
and withdrawal of separable electrical connectors which are
accelerated aging test; then the resistances are measured again.
harmful to the electrical performance of the connector.
All samples are separated (withdrawn), exposed to an acceler-
1.2 This test method is limited to electrical connectors
ated aging test in the uninserted condition, removed from the
designed for use in applications where the current through any
test, reinserted, and resistances measured again. The various
one connection in the connector does not exceed 5 A, and
resistance measurements are compared to detect effects of the
where the connector may be separated a number of times
wear and aging on electrical performance.
during the life of the connector.
1.3 This test method is limited to electrical connectors
4. Significance and Use
intended for use in air ambients where the operating tempera-
4.1 Materials for electrical connector contacts must satisfy a
ture is less than 65°C.
number of requirements in the areas of electrical, mechanical,
1.4 This standard does not purport to address all of the
and economic characteristics. The stability of electrical prop-
safety concerns, if any, associated with its use. It is the
erties is one of the most important of these characteristics.
responsibility of the user of this standard to become familiar
Wear of contact surfaces may adversely affect these electrical
with all hazards including those identified in the appropriate
properties, especially in designs where the contact surfaces are
Material Safety Data Sheet for this product/material as pro-
relatively thin coatings. This test method provides a means to
vided by the manufacturer, to establish appropriate safety and
compare various material systems on a basis relevant to their
health practices, and determine the applicability of regulatory
application in electrical connector contacts.
limitations prior to use.
4.2 Repeated insertion and withdrawal of a connector may
2. Referenced Documents cause wear or other mechanical damage to the electrical
contact surfaces, rendering those surfaces more susceptible to
2.1 ASTM Standards:
environmental degradation. This test method is intended to
B 539 Test Methods for Measuring Resistance of Electrical
detect degradation of the electrical properties of the connector
Connections (Static Contacts)
3 by such processes.
2.2 Military Standard:
4.3 This test method describes procedures for conducting
MIL-STD-1344A Test Methods for Electrical Connectors
wear and durability testing of electrical connectors; the proce-
3. Summary of Test Method
dures produce quantitative results. These results may be used
to compare the performance of different connector designs so
3.1 Sample connectors are wired for precision resistance
that meaningful design choices can be made. Such results may
measurements of each test contact. The samples are divided
also be used to compare the performance of a connector to a
into two groups; then resistance measurements are made of
previously established standard to evaluate the quality of the
each test contact. The connectors in one group undergo a
samples under test.
number of insertion/withdrawal cycles appropriate for the
4.4 The test results obtained from this test method are
limited in their applicability to connector combinations that are
This test method is under the jurisdiction of ASTM Committee B02 on
equivalent in design and manufacture to those actually tested.
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
4.5 The user is cautioned that the conditions in this test
B02.11 on Electrical Contact Test Methods.
should be compared to the conditions that the connector will
Current edition approved June 10, 2003. Published July 2003. Originally
approved in 1988. Last previous edition approved in 1997 as B 794 – 97.
experienceintheintendedapplicationinordertodeterminethe
Annual Book of ASTM Standards, Vol 03.04.
relevance of this test method to the particular needs of the user.
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
For example, the environmental stress in this test method is
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
B794–97 (2003)
TABLE 1 Environmental Test Sequence
lessseverethancertainindustrialandmarineenvironmentsand
therefore test results are not directly applicable to predict the
NOTE 1—Tolerance on temperature control is 62°.
performance of product intended for use in such areas.
4.6 It is recommended that this test method be used in one Step Elapsed Time, Temperature, Relative Humidity,
h °C %
of two ways. First, it may be used to evaluate and report the
1 0–2.5 ascending, 25–65 92 6 3
performance of a particular connector system. In such a case,
2 2.5–5.5 65 92 6 3
it is appropriate to report the results in a table in the format
3 5.5–8 descending, 65–25 87 6 8
shown in Fig. 1 and to state “The results shown in the table 4 8–10.5 ascending, 25–65 92 6 3
5 10.5–13.5 65 92 6 3
were obtained for (insert connector designation or description)
6 13.5–16 descending, 65–25 87 6 8
when tested in accordance with ASTM Standard B 794,
7 16–24 25 92 6 3
Method __ , Procedure __ .” Second, it may be used to impose
requirements for acceptance of product. In this case, limits for
the values shown in Fig. 1 must be established prior to product
sample shall be positioned with at least 100 mm separating it
acceptance testing. Such limits may be established by various
from the nearest wall of the test chamber. The test chamber
methodssuchasbyevaluationofproductwhichisknowntobe
design and operation procedure shall conform to the require-
acceptable or by application of appropriate experience. These
ments contained in MIL-STD-1344A, Method 1002.2.
limits must be documented in a manner that the entity
5.2 An instrument is required for measuring resistance by
performing the product test can refer to the limits to determine
the four-wire method. This instrument shall operate within the
if the test product conforms to such limits. A purchaser may
limits on current and open-circuit voltage set forth in Test
wish to supply a table of limits and include on the purchase
Methods B 539, Test Method C. The instrument shall be
order a statement similar to: “The product, when tested in
capable of measuring a resistance less than 0.100 V with a
accordance with ASTM Standard B 794, Method __ , Proce-
resolution of 0.0001 V. For a resistance 0.100 V or larger, the
dure __ , shall meet the limits in the supplied table.” This table
instrument shall be capable of measuring it with a resolution of
supplied by the purchaser may set limits on all of the values in
0.1 % of the resistance value.
Fig. 1, or only on a subset of those values that the purchaser
deems adequate to ensure the performance of the product.
6. Sampling and Test Specimens
6.1 Selection of Sample Connectors—Obtain sufficient
5. Apparatus
sample connectors so that the electrical resistance of at least
5.1 Environmental Test Chamber, capable of controlling the
200 contacts contained in at least 20 separate connectors will
testambientinaccordancewiththesequenceshowninTable1.
be measured in the test. Obtain sample connectors that are
The test chamber shall be sufficiently large that each test
representative of those that will be used in the intended
application. Recognize that a connector consists of two halves
and both halves must be representative of the product to be
used. In some cases one half will be a conductive area or pad
on a printed wiring-board surface, therefore printed wiring
boards must be obtained that have representative conductive
pads. Specifically, the conductive pads shall be manufactured
to the same requirements as those that will be required of parts
to be used in the system application. These requirements will
normally cover the manufacturing process, thickness, compo-
sition,hardness,androughnessofboththefinishcoatingandof
any underplating or undercoating. Protective treatments, if
used, shall also be specified. For the purpose of connector
testing, such printed wiring boards are generally fabricated
with appropriate circuitry to permit four-wire resistance mea-
surements.
6.2 Selection of Sample Contacts—In the case where the
samples are multicontact connectors and electrical measure-
ments are performed only on a fraction of the total number of
contacts, the contacts measured shall be distributed throughout
the field of contacts. Measure the corresponding contacts in
each sample connector.
7. Conditioning
7.1 An electrical measurement laboratory is required in
which the ambient temperature is controlled to 23 6 5°C and
the relative humidity is held below 60 %. This laboratory need
FIG. 1 Sample Format for Reporting Results not be dedicated to this test program to the exclusion of other
B794–97 (2003)
uses so long as those other uses do not degrade the quality of
data obtained on the connector test samples.
8. Procedure
8.1 Selection of Test Method—Select a test method from the
following table which is appropriate for connector design and
application.
Method Number of Insertions
A5
B10
C25
D50
E 100
F 200
G 400
H (number selected per agreement
between producer and user)
8.2 Sample Preparation:
8.2.1 Assemble the connectors into mounting plates, guides,
fixtures, racks, or similar apparatus if such apparatus is
generally used in the actual application of the connector.
Performsuchassemblyatthetimeinthesamplewiringprocess
that best simulates the typical manner in which the connectors
are assembled into a system.
8.2.2 Wire samples for evaluation by this test method for
electrical resistance measurements before the two connector
halves are plugged together. The wiring and resistance mea-
suring circuitry shall be of the four-wire type as described in
Test Methods B 539. Do the wiring in a manner that is typical
of the way the connector would be wired in service, and
especially in a manner that does not introduce unrealistic
contaminants or mechanical stresses on the connector. Do not
FIG. 2 Sample Data Sheet
perform cleaning, lubrication, or other treatments of the
connectorunlesssuchtreatmentsarespecifiedbytheconnector
manufacturer or user as the required procedure for the appli-
Test samples must be allowed to come to equilibrium in this
cation of the particular connector under test.
ambient for a minimum of 1 h before electrical measurements
8.2.3 Wire at least one reference resistor for resistance
or connector insertion/withdrawal operations begin. All con-
measurements in such a manner that its resistance may be
nector insertion/withdrawal operations are done with the con-
measuredusingthesameinstrumentationandproceduresasare
nector disconnected from any power source.
used for the test contacts. It is suggested that this reference
8.3.3 Perform all resistance measurements under dry-circuit
resistor be a length of wire or a path on a printed wiring board
conditions as specified in Test Methods B 539, Test Method C.
with a resistance of the same order of magnitude as that of
In addition, use a suitable method to cancel small potentials
typical test contacts. Measure and record the resistance of this
that may be present in the measurement circuit. Suitable
reference resistor each time that the test contacts are measured.
methods are (1) measuring the resistance with the current
Expose this reference resistor to the same test environments as
flowing one direction through the test contact, reversing the
the test contacts and generally treat the resistor in the same
current flow and remeasuring resistance, and averaging the two
manner as the test contacts.
resistance measurements; (2) measuring voltage drop across
8.2.4 Labeltheconnectorsandindividualcontactsthereinin
the test contact with a constant d-c current flowing, measuring
such a manner that each test contact is uniquely identified.
voltage across the contact with no impressed current, and
Randomly select one half of the connectors (10 connectors if
subtracting the second voltage from the first and using the
20 connectors is the total sample size) to undergo wear testing,
result to calculate resistance; or (3) measuring resistance using
and refer to these as the “wear test samples.” Insert the other
an a-c method. The user shall select one method and use it
halfoftheconnectorsonlyonceatthebeginningofthetestand
throughout the experiment.
refer to these as the “control samples.”
8.3.4 Make all resistance measurements in such a manner
8.3 Methods and Procedures for Resistance Measurements:
that the value is recorded with the resolution meeting the
8.3.1 Prepare data sheets such that all information shown in following requirements: For contacts with a measured resis-
the sample data sheet illustrated in Fig. 2 may be recorded for
tance less than 0.100 V, record the resistance with a resolution
each test contact. of 0.0001 V or better. For contacts with resistance of 0.100 V
8.3.2 Perform all electrical measurements and wear tests in or greater, record the resistance measurement with a resolution
the electrical measurements laboratory discussed in Section 7. of 0.1 % or better. If the resistance changes during the
B794–97 (2003)
measurement such that after about5sa stable value of the 8.5.1 Selection of Test Procedure—Two alternative proce-
required resolution cannot be determined, record an estimate dures are provided: the user must select one based on the test
and note that the resistance is unstable. objectivesandavailablefacilities.Theproceduresdifferonlyin
their treatment of vibration during the test. ProcedureAplaces
8.3.5 After each measurement of the reference resistor,
no requirements on the measurement or control of vibration
compare the new measured value to the initial value. If the
leve
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