IEC 61340-4-6:2010

IEC 61340-4-6
®

Edition 1.0 2010-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Electrostatics –
Part 4-6: Standard test methods for specific applications – Wrist straps

Electrostatique –
Partie 4-6: Méthodes d’essai normalisées pour des applications spécifiques –
Bracelets de conduction dissipative

IEC 61340-4-6:2010

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IEC 61340-4-6
®

Edition 1.0 2010-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Electrostatics –
Part 4-6: Standard test methods for specific applications – Wrist straps

Electrostatique –
Partie 4-6: Méthodes d’essai normalisées pour des applications spécifiques –
Bracelets de conduction dissipative

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX R
ICS 17.200.99; 29.020 ISBN 978-2-88912-472-5

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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– 2 – 61340-4-6  IEC:2010
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Testing levels and performance limits . 8
5 Test methods . 9
5.1 Wrist strap continuity and resistance test . 9
5.1.1 Equipment . 9
5.1.2 Procedure . 10
5.1.3 Reporting . 10
5.2 Cuff resistance test . 10
5.2.1 Equipment . 10
5.2.2 Procedure (interior resistance) . 10
5.2.3 Procedure (exterior resistance) . 10
5.2.4 Reporting . 11
5.3 Cuff size requirements . 11
5.3.1 Equipment . 11
5.3.2 Self-adjusting cuffs . 11
5.3.3 “One-size-fits-all” cuffs . 11
5.4 Breakaway force. 11
5.5 Connection integrity . 11
5.5.1 Equipment . 11
5.5.2 Procedure . 11
5.5.3 Reporting . 12
5.6 Ground cord extendibility . 12
5.7 Bending life test . 12
5.7.1 Equipment . 12
5.7.2 Procedure . 12
5.7.3 Reporting . 12
5.8 Manufacturer’s identification . 12
5.9 Identification of non-standard resistance value . 12
5.10 Wrist strap resistance . 13
5.10.1 Equipment . 13
5.10.2 Procedure . 13
5.10.3 Reporting . 13
5.11 Wrist strap system continuity test . 13
5.11.1 Equipment . 13
5.11.2 Procedure (integrated checker) . 13
5.11.3 Procedure (ohmmeter) . 13
5.11.4 Reporting . 13
Annex A (informative) Application guidelines . 17
Annex B (informative) Construction guidelines . 19


Figure 1 – Wrist strap resistance test apparatus . 14

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61340-4-6  IEC:2010 – 3 –
Figure 2 – Flex test apparatus . 15
Figure 3 – Wrist strap system resistance test . 16

Table 1 – Evaluation testing . 9
Table 2 – Acceptance testing . 9
Table 3 – Functional testing . 9

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– 4 – 61340-4-6  IEC:2010
INTERNATIONAL ELECTROTECHNICAL COMMISSION
______________

ELECTROSTATICS –

Part 4-6: Standard test methods for specific applications –
Wrist straps


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61340-4-6 has been prepared by IEC technical committee 101:
Electrostatics.
The text of this standard is based on ANSI/ESD S1.1-2006. It was submitted to the National
Committees for voting under the Fast Track Procedure.
This bilingual version (2011-04) replaces the English version.

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61340-4-6  IEC:2010 – 5 –
The text of this standard is also based on the following documents:
FDIS Report on voting
101/291/FDIS 101/296/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 61340 series, under the general title Electrostatics, can be found
on the IEC website.
Le comité a décidé que le contenu de cette publication ne sera pas modifié avant la date de
stabilité indiquée sur le site web de la CEI sous "http://webstore.iec.ch" dans les données
relatives à la publication recherchée. A cette date, la publication sera
• reconduite,
• supprimée,
• remplacée par une édition révisée, ou
• amendée.

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– 6 – 61340-4-6  IEC:2010
INTRODUCTION
This part of IEC 61340 has been developed to establish test methods for evaluating the
electrical and mechanical attributes of wrist straps used in an electrostatic control program.
Wrist straps are intended to connect the user to electrical ground, thus preventing
electrostatic charge on a user’s body from attaining a level that may damage ESD susceptible
devices or assemblies.
Test methods and performance limits for evaluation, acceptance, and functional testing are
provided. Application and construction guidance is included in the annexes.

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61340-4-6  IEC:2010 – 7 –
ELECTROSTATICS –

Part 4-6: Standard test methods for specific applications –
Wrist straps



1 Scope
This part of IEC 61340 provides electrical and mechanical test methods and performance
limits for evaluation, acceptance and functional testing of wrist straps.
This standard is intended for testing wrist straps and wrist strap systems used for the
grounding of personnel engaged in working with ESD sensitive assemblies and devices.
It does not address constant monitoring systems.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
1
ESD ADV1.0, Glossary of terms
3 Terms and definitions
For the purposes of this document, the following terms and definitions, in addition to those
specified in the ESD association glossary of terms, shall apply.
3.1
wrist strap
assembled device consisting of a wrist cuff and ground cord that provides electrical
connection of a person’s skin to ground
3.2
wrist strap system
wrist strap when properly worn by a person, where the electrical path includes the person, the
cuff and the ground cord
3.3
cuff
portion of the wrist strap worn on the wrist
NOTE The cuff maintains electrical contact with a person’s skin.
3.4
ground cord
portion of the wrist strap that provides flexibility of movement while completing the electrical
circuit between the cuff and ground
___________
1
 ESD Association, 7900 Turin Rd, Bldg. 3, Ste. 2, Rome, NY 13440-2069, 315-339-6937, www.esda.org

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– 8 – 61340-4-6  IEC:2010
3.5
evaluation testing
stringent testing of a wrist strap to determine its electrical and mechanical performance
abilities
NOTE Data are in the form of values from laboratory testing.
3.6
acceptance testing
incoming tests to confirm proper marking and electrical functionality
NOTE Data are in the form of visual inspection records, and values or pass/fail notation.
3.7
functional testing
end-use testing to confirm electrical functionality
NOTE Data are in the form of pass/fail notation or values.
3.8
current-limiting resistance
resistance value incorporated in series with the wrist strap’s electrical path to ground
NOTE This resistance limits electrical current that could pass through the ground cord in the event of inadvertent
user contact with electrical potential.
3.9
resistance range
user-specified upper and lower resistance values which define the user-acceptable resistance
values of a wrist strap or wrist strap system
3.10
strain relief
construction feature designed to protect the connections and cord from premature failure
3.11
breakaway force
force required to disconnect the ground cord from the cuff
4 Testing levels and performance limits
This part of IEC 61340 specifies different types of testing for wrist straps. Tables 1, 2 and 3
detail the three types of testing with the associated limits and paragraph references to test
methods. The methods provide appropriate tests for the different levels of wrist strap
examination. The “evaluation tests” are laboratory tests for measuring the performance of a
wrist strap or for the comparison of wrist straps. “Acceptance tests” provide methods for
incoming goods inspection. Finally, the “functional test” is a simple check of electrical
continuity. This test shall be used on a regular, user-defined basis, to ensure that the wrist
strap is electrically functional.

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61340-4-6  IEC:2010 – 9 –
Table 1 – Evaluation testing
Electrical Limit Test ref.
Wrist strap continuity and resistance 1 mΩ ± 20 %, or user defined value 5.1
Cuff resistance Interior:
≤100 kΩ or user defined value 5.2
Exterior:
≥10 mΩ

Mechanical Limit Test ref.
Cuff size Defined 5.3
Breakaway force 5.4
> 0,45 kg (1 lb), < 2,3 kg (5 lb)
Connector and cord integrity > 2,3 kg (5 lb) and > 66 % of cord strength 5.5
Ground cord extendibility Extension to manufacturer’s specified 5.6
length with no continuity loss
Bending life ≥ 16 000 cycles 5.7

Marking Limit Test ref.
Manufacturer’s identification Logo and/or name 5.8
Identification of non-standard Red feature. Value marked 5.9
Resistance value

Table 2 – Acceptance testing
Electrical Limit Test ref.
Wrist strap resistance 1 mΩ ± 20 %, or user defined value 5.10

Marking Limit Test ref.
Manufacturer’s identification Logo and/or name 5.8
Identification of non-standard Red feature. Value marked 5.9
Resistance value

Table 3 – Functional testing
Electrical Limit Test ref.
Wrist strap system continuity 5.11
“Pass” or ≤ 10 mΩ, or user defined value
5 Test methods
Refer to Tables 1, 2 and 3 for test method applications.
5.1 Wrist strap continuity and resistance test
This test measures the value of the current-limiting resistance and assures continuity between
the discrete parts of the wrist strap.
5.1.1 Equipment
The equipment shall consist of the following:

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– 10 – 61340-4-6  IEC:2010
• A test fixture (see Figure 1) comprising an insulative stand and two 2,54 cm (1 “) diameter
stainless steel cylinders, with one cylinder fixed to the stand directly above the second.
The second cylinder will weigh 0,11 kg (0,25 lb) and is mounted in a slot in the stand that
allows free vertical movement;
• an ohmmeter or other instrument(s) capable of reading from at least 50 kΩ to at least
100 m mΩ with a test voltage of 7 V to 30 V DC open circuit;
• six samples of wrist straps.
5.1.2 Procedure
Using the fixture shown in Figure 1, place the cuff around the cylinders with the cuff interior
toward the cylinders and the ground cord connector on the right side and parallel to the
cylinders, evenly spaced between the cylinders. Allow the 0,11 kg (0,25 lb) cylinder to move
freely and stress the cuff.
Connect the ground cord to the cuff.
Connect the ohmmeter to the top cylinder and to the ground connector of the ground cord.
Measure and record the resistance.
Repeat the test for a total of six wrist straps.
5.1.3 Reporting
Report the resistance for each wrist strap.
5.2 Cuff resistance test
Resistance of the cuff interior and exterior is determined.
5.2.1 Equipment
See 5.1.1.
5.2.2 Procedure (interior resistance)
Using the test fixture from 5.1.1, Figure 1, place a cuff around the cylinders with the cuff
interior toward the cylinders and the ground cord connector on the right side and parallel to
the cylinders, evenly spaced between the cylinders. Allow the 0,11 kg (0,25 lb) cylinder to
move freely and stress the cuff.
Connect the ohmmeter to the top cylinder and the ground cord connector on the cuff. Measure
and record the resistance value.
Repeat procedure for a total of six cuffs.
5.2.3 Procedure (exterior resistance)
Place a cuff around the cylinders (Figure 1) with the cuff exterior toward the cylinders and the
ground cord connector on the right side and parallel to the cylinders, evenly spaced between
the cylinders. Allow the 0,11 kg (0,25 lb) cylinder to move freely and stress the cuff.
Connect the ohmmeter to the top cylinder and the ground cord connector on the cuff. Measure
and record the resistance value.
Repeat procedure for a total of six cuffs.

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61340-4-6  IEC:2010 – 11 –
5.2.4 Reporting
Report the interior resistance and exterior resistance of each cuff.
5.3 Cuff size requirements
Cuff sizes are determined by the cuff’s ability to fit over a specifically sized cylinder. A cuff’s
ability to expand to fit over a hand, yet contract to fit snugly around a wrist is determined by
fitting the cuff over specifically sized large and small cylinders.
5.3.1 Equipment
The equipment shall consist of the following:
• 1 cylinder having an outside diameter of 4,3 cm (1,70 “)
• 1 cylinder having an outside diameter of 5,3 cm (2,10")
• 1 cylinder having an outside diameter of 8,25 cm (3,25")
• 1 cylinder having an outside diameter of 8,9 cm (3,50")
5.3.2 Self-adjusting cuffs
“Large”-sized self-adjustable expanding metal or fabric cuffs shall fit snugly onto a 5,3 cm
(2,10") diameter cylinder, and be capable of easily fitting over a 8,9 cm (3,50") diameter
cylinder.
“Small”-sized self-adjustable expanding metal or fabric cuffs shall fit snugly onto a 4,3 cm
(170") diameter cylinder, and be capable of easily fitting over a 8,25 cm (3,25") diameter
cylinder.
5.3.3 “One-size-fits-all” cuffs
“One-size-fits-all” cuffs shall fit snugly on a 4,3 cm (1,70") diameter cylinder and be capable of
sufficient expansion to fit over a 8,9 cm (3,5") cylinder.
5.4 Breakaway force
With the ground cord connected to the cuff in a normal manner, a force of ≥ 0,45 kg (1 lb) but
≤ 2,3 kg (5 lb) applied to the ground cord, in the normal disconnect direction, shall be required
to separate the ground cord from the cuff.
5.5 Connection integrity
The strengths of the ground cord, the ground cord’s attachment to the ground, and cuff
connectors are determined.
5.5.1 Equipment
The equipment shall consist of the following:
• tensile tester capable of 6,35 cm (2,5") per minute travel;
• grippers for tensile tester;
• chart recorder.
5.5.2 Procedure
Using the tensile tester and chart recorder, test and record the tensile strength (breaking point)
of the ground cord, the ground connector to the ground cord, and the cuff connector to the
cord. Repeat the test for a total of six ground cords.

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– 12 – 61340-4-6  IEC:2010
5.5.3 Reporting
Report the tensile strength of each connector.
5.6 Ground cord extendibility
Retractable-type ground cords shall be capable of being extended to the manufacturer’s
specified length without pulling the cuff away from the user’s wrist to the extent that electrical
continuity, as measured in 5.11, is interrupted.
5.7 Bending life test
Ground cord flex life is determined.
5.7.1 Equipment
The equipment shall consist of the following:
• mechanical ground cord flex tester: this is a machine that drives a rocker plate through an
arc of 120° at a rate of approximately 2 000 cycles per hour (see Figure 2);
NOTE 1 A flex tester with a larger number of rocker plates is acceptable.
NOTE 2 Ground cords are attached to the rocker plates by means of a mounting that simulates alternately
the cuff connector and the ground connector.
• 45 kg (1 lb) weights;
• resistance meter with a test voltage ≤ 30 V.
5.7.2 Procedure
Attach one end of a ground cord to a rocker plate. Connect the opposite end to a 0,45 kg (1 lb)
weight and allow the ground cord to hang freely. Connect the resistance monitoring cable to
the ground cord conductor at the weighted end.
Start the flex tester.
Six cords shall be tested with the cuff connection attached to rocker plate and six cords shall
be tested with the ground connection attached to rocker plate.
5.7.3 Reporting
Ground cord failure is defined as the total resistance of the circuit exceeding 1,25 mΩ (or user
defined value), or when there is visible evidence of mechanical failure in the cord jacket or
strain relief. Each ground cord shall have a minimum life of at least 8 000 cycles and the
average of all samples tested shall have a minimum life of 16 000 cycles.
5.8 Manufacturer’s identification
Wrist straps shall have the manufacturer’s name or logo embossed, molded or otherwise
permanently marked in a prominent location.
5.9 Identification of non-standard resistance value
Wrist straps incorporating a resistance of non-standard value (other than 1,0 mΩ ± 20 %)
shall be identified by having a prominent feature, red in colour, on the wrist strap. Additionally,
the value of the non-standard resistance shall be marked on the portion of the wrist strap that
contains the resistance. Only wrist straps incorporating a non-standard value shall use the
colour red on any portion of the wrist strap.

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61340-4-6  IEC:2010 – 13 –
5.10 Wrist strap resistance
This test determines the resistance of the wrist strap.
5.10.1 Equipment
The equipment shall consist of the following:
• an mΩ or other instrument(s) capable of reading from 50 kΩ to at least 100 mΩ with a test
voltage of 7 V to 30 V DC open circuit.
5.10.2 Procedure
Connect the cuff to the ground cord. Attach the ground cord to an ohmmeter lead. Connect
the skin contact area of the cuff to the other ohmmeter lead. Measure the resistance of the
wrist strap. Repeat the test for a
...