ESD TR53-01-06
for the Protection of Electrostatic
Discharge Susceptible Items
Compliance Verification of ESD Protective
Equipment and Materials
Electrostatic Discharge Association
7900 Turin Road, Bldg. 3
Rome, NY 13440
CAUTION
NOTICE
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Published by:
Electrostatic Discharge Association
7900 Turin Road, Bldg. 3
Rome, NY 13440
Copyright © 2006 by ESD Association
All rights reserved
No part of this publication may be reproduced in any form, in
an electronic retrieval system or otherwise, without the prior
written permission of the publisher.
Printed in the United States of America
(This foreword is not part of ESD Association Technical Report TR53-01-06)
Foreword
This technical report describes the test methods and instrumentation that can be used to
periodically verify the performance of ESD protective equipment and materials. After ESD
protective equipment and materials are installed and in their actual use locations, these
compliance verification test methods are recommended to provide a baseline for comparison with
future compliance verification tests. The objective of these test methods is to identify if significant
performance changes in ESD equipment and materials have occurred over time.
The wide variety of ESD protective equipment and materials, and the environment in which they
are used, may require test setups different from those described in this technical report. Users of
this technical report may need to adapt the test method and setups (as required) to produce
meaningful data for their own application. Organizations who perform these tests will also need
to determine the time interval between compliance verification based on how critical the ESD
protective equipment and materials are to their static control program.
All test methods in this document are based on current standards, standard test methods and
standard practices currently published by the ESD Association.
This technical report was prepared by the 53.0 Compliance Verification Subcommittee. At that
time the 53.0 Compliance Verification Subcommittee had the following members:
Timothy Jarrett, Chair
Boston Scientific
Eugene Chase
Electro-Tech Systems, Inc.
Cheryl Checketts
General Dynamics
Melissa Feeney-Jolliff
Aerospace Corp.
Gene Felder
Desco Industries, Inc.
Bill Ricker
Ricker Engineering Services
Jeff Salisbury
Seagate Technology
Sarah Smith
Walker Forge
Fred Tenzer
Desco Industries, Inc.
i
TABLE OF CONTENTS
PURPOSE ....................................................................................................................................... 1
SCOPE ............................................................................................................................................ 1
PERSONNEL SAFETY ................................................................................................................... 1
TEST EQUIPMENT ......................................................................................................................... 2
ESD PROTECTIVE EQUIPMENT AND MATERIALS
Grounding / Bonding Systems..................................................................................................... 4
Worksurfaces ................................................................................................................................. 6
Wrist Straps.................................................................................................................................... 9
Constant Monitors ....................................................................................................................... 11
Footwear....................................................................................................................................... 12
Flooring ........................................................................................................................................ 15
Personnel Grounding with Garment.......................................................................................... 17
Garments ...................................................................................................................................... 19
Air Ionizers ................................................................................................................................... 21
Seating.......................................................................................................................................... 23
Mobile Equipment (Carts) ........................................................................................................... 25
Packaging..................................................................................................................................... 27
ANNEX A....................................................................................................................................... 28
ii
PURPOSE
The purpose of this technical report is to provide periodic verification test methods and troubleshooting guidance for ESD protective equipment and materials to assist the user when complying
with the Compliance Verification Plan Requirements of ANSI/ESD S20.20.
SCOPE
This document describes periodic verification testing for the following ESD Protective Equipment
and Materials:
•
Grounding / Bonding Systems
•
Worksurfaces
•
Wrist Straps
•
Constant Monitors
•
Footwear
•
Flooring
•
Personnel Grounding with Garment
•
Garments
•
Air Ionizers
•
Seating
•
Mobile Equipment (Carts)
•
Packaging
PERSONNEL SAFETY
The procedures and equipment described in this document may expose personnel to hazardous
electrical conditions. Users of this document are responsible for selecting equipment that
complies with applicable laws, regulatory codes and both external and internal policy. Users are
cautioned that this document cannot replace or supersede any requirements for personnel safety.
Ground fault circuit interrupters (GFCI) and other safety protection should be considered
wherever personnel might come into contact with electrical sources. Electrical hazard reduction
practices should be exercised and proper grounding instructions for equipment must be followed.
1
Test Equipment
If user defined specifications are outside the limits of the test equipment, the user should define
test equipment that will measure their specific requirements. Test equipment should be used and
calibrated according to the manufacturer’s recommendations.
DC Ohmmeter
The meter should be capable of measuring a D.C. resistance of 0.1 ohm through 1.0 megohm (or
other added resistance value) with an accuracy of ± 10% of the value being measured.
Electrode
Cylindrical 2.27 ± 0.06 kg (5 lb ± 2 oz) with a diameter of 63.5 ± 0.25 mm (2.5 ± 0.1 inches)
having a contact of electrically conductive material with a Shore-A (IRHD) durometer hardness
between 50 and 70. The resistance between two electrodes should be less than 1.0 x 103 ohms
when measured at 10 volts on a metal surface.
Hand-Held Electrode
A stainless steel cylinder, 75 mm (3 inches) or greater in length, and 25 mm (1 inch) in diameter.
A banana plug receptacle or screw connector is normally attached to one end of the cylinder. All
dimensions nominal.
Foot Electrode
A conductive metal plate, 305 mm square (12 inches). All dimensions nominal.
AC Outlet Analyzer
An AC Outlet Analyzer can be used to indicate the presence of the equipment-grounding
conductor. Please note that some AC Outlet Analyzers may not be able to differentiate Ground
and Neutral wire reversals, Hot and Neutral wire reversals and Hot and Ground wire reversals, or
determine if the impedance to ground of the equipment-grounding conductor is within the
company specification.
AC Circuit Tester (Impedance Meter)
The meter should be capable of measuring the impedance of the equipment-grounding conductor
from a receptacle (power outlet used for establishing the AC equipment ground) to the neutral
bond at the main service equipment panel. The meter should also verify wiring orientation.
2
Test Equipment
Insulative Support Surface
A flat insulative plate sized to support the ESD Protective Equipment or Material under test. The
resistance of the insulative surface should be greater than 1.0 x 1013 ohms per square when
measured per ASTM D-257.
Charged Plate Monitor (CPM)
A Charged Plate Monitor (CPM) as described in ANSI/ESD STM3.1, or a portable verification kit
(as described in ESD SP3.3) may be used for the compliance verification of air ionizers. Portable
verification kits are commercially available and typically consist of four components: 1) field
meter, 2) detachable (isolated conductive) plate, 3) plate charger and 4) ground cord.
3
Grounding / Bonding Systems
Compliance Verification
This periodic test procedure is in part based on the following publication(s):
•
ANSI/ESD S6.1, Grounding
•
ANSI/NFPA 70, National Electric Code
Objective
The objective of this periodic test procedure is to verify that the various Grounding / Bonding
Systems of an ESD Protective Workstation (and/or ESD Protected Area) are within the maximum
resistance value allowed by the user's specification.
An ESD Protective Workstation connects all ESD worksurfaces, fixtures, handling equipment and
personnel grounding devices to a Common Point Ground. The Common Point Ground is
connected to the ESD Grounding/Bonding Reference Point, which in most cases will be the AC
equipment ground. If an Auxiliary ground is used, it should be electrically bonded to the AC
equipment ground.
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
DC Ohmmeter
•
AC Outlet Analyzer
•
AC Circuit Tester (Impedance Meter)
•
Two test leads of sufficient length
ESD Protective Workstation
4
Grounding / Bonding Systems
Compliance Verification
Test Procedure
Electrical Receptacles
•
Grounding procedures must remain consistent with the National Electric Code (NEC) and
other applicable codes. The Electrical Receptacle Verification test is intended to check for
the proper wiring of the equipment-grounding conductor that is used as the ESD
Grounding/Bonding Reference Point.
•
An AC Outlet Analyzer can be used to indicate the presence of the equipment-grounding
conductor. Please note that some AC Outlet Analyzers may not be able to differentiate
ground and neutral wire reversals, hot and neutral wire reversals and hot and ground wire
reversals, or determine if the impedance to ground of the equipment-grounding conductor is
within the company specification.
•
An AC Circuit Tester can be used to verify the integrity of the electrical circuit wiring as
needed.
o
Connect the AC circuit tester (impedance meter) to the AC outlet or receptacle containing
the equipment-grounding conductor that will be used for the ESD Grounding/Bonding
Reference Point.
o
Verify the following conditions:
ƒ
ƒ
ƒ
ƒ
Neutral and equipment grounding conductor wires are present and not connected
to each other at the receptacle (outlet).
Hot and neutral wires are not reversed.
Hot and equipment-grounding conductors are not reversed.
Impedance of the equipment-grounding conductor is not greater than 1.0 ohm.
Personnel Groundable Points
•
Operate the DC ohmmeter according to the manufacturer's instructions.
•
Connect two test leads to the DC ohmmeter.
•
Connect or place one test lead to the personnel groundable point and the other test lead to
the ground reference.
•
Verify the resistance and continue testing personnel groundable points.
Troubleshooting
Electrical Receptacle Failures
•
Any AC outlet or directly connected equipment (hard wire) that fails the Receptacle Wiring
Verification tests must be corrected by qualified personnel before further use or testing.
Personnel Groundable Point Failures
•
Visually and mechanically confirm that all termination hardware and grounding wires are not
inadvertently loose, broken, or disconnected.
•
Test the resistance of the personnel groundable point to common point ground.
•
Test the resistance of the common point ground to AC Grounding/Bonding Reference Point.
5
Worksurfaces
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ESD ADV53.1, ESD Protective Workstations
•
ANSI/ESD S4.1, Worksurfaces – Resistance Measurements
•
ANSI/ESD S6.1, Grounding
Objective
The objective of this periodic test procedure is to verify that the ESD worksurface is electrically
bonded to the ground reference and is within the minimum and maximum resistance allowed by
the user's specification.
This periodic test procedure can also be used for the measurement of shelves, drawers and other
ESD protective storage equipment surfaces.
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
An integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring at least 1.0 x 1010 ohms with a test voltage of 10 and 100 volts
(± 10%) DC open circuit.
•
One electrode
•
Two test leads of sufficient length
•
DC Ohmmeter
CL
CL
ESD Worksurface Test
6
Worksurfaces
Compliance Verification
Test Procedure
•
Do not clean the ESD worksurface immediately prior to verification.
•
Remove all ESD sensitive items from the ESD worksurface.
•
Conductive items and AC-powered equipment having separate paths to the ground reference
should remain connected to their grounds at the ESD worksurface being verified.
•
Connect one end of the first test lead to the electrode, and the other end of the first test lead
to the integrated checker or meter.
•
Connect one end of the second test lead also to the integrated checker or meter, and the
other end of the second test lead to ground reference.
•
Place the electrode in the center of the ESD worksurface and apply 10 volts.
•
Wait for the integrated checker or meter to stabilize.
•
If the indicated resistance is less than 1.0 x 106 ohms, continue testing.
•
If the indicated resistance is equal to or greater than 1.0 x 106 ohms, switch the integrated
checker or meter to 100 volts and retest the ESD worksurface.
•
Tests should include those ESD worksurface areas that are subject to wear or are visibly
dirty.
Troubleshooting
Visual / Mechanical Check
•
Visually and mechanically confirm that all termination hardware and grounding wires are not
inadvertently loose, broken or disconnected.
•
Examine the ESD worksurface to ensure it is not soiled or worn, which could cause increased
surface resistance. If soiled, clean the ESD worksurface with an approved cleaner. Ensure
the surface is completely dry before retesting. Periodic cleaning is recommended to maintain
proper electrical function of all ESD worksurfaces.
•
When checking ESD worksurface mats:
o
Check the connection of the mat fastener to the mat.
o
Check the connection of the ground cord to the mat fastener.
o
Check the connection of common point ground to the ground cord.
o
Check the connection of equipment ground to common point ground.
7
Worksurfaces
Compliance Verification
Electrical Test
•
Verify the test equipment is operating properly, check/service the battery (if battery operated),
following the manufacturer’s operating instructions for proper operation.
•
Examine the electrode for dirt buildup. Remove surface contamination by following the
manufacturer’s recommendations. If using liquids to clean electrode, allow to the electrode to
dry before retesting.
•
With an integrated checker or meter, test the resistance of the ESD worksurface to the
groundable point. The mechanical connection between the groundable point and the
worksurface could become compromised by changes in humidity.
•
With a DC ohmmeter, test the resistance of the groundable point to common point ground.
•
With a DC ohmmeter, test the resistance of the common point ground to equipment ground.
•
Ensure the environmental ambient conditions have not dried out the worksurface material.
To determine this condition, the resistance between two locations on the top of the
worksurface (point-to-point) can be performed per ANSI/ESD S4.1 using an integrated
checker or meter and two electrodes with test leads.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
8
Wrist Straps
Compliance Verification
This periodic test procedure is in part based on the following publication(s):
•
ANSI/ESD S1.1, Wrist Straps
Objective
The objective of this periodic test procedure is to verify that the total series resistance of all of the
elements in the wrist strap system is within the minimum and maximum resistance allowed by the
user's specification.
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
Integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring from 5.0 x 104 ohms to at least 1.0 x 1010 ohms with a test voltage
between 7 and 30 volts DC open circuit. Some integrated checkers require manual selection
to wrist strap resistance test ranges.
•
Hand-held electrode
•
One test lead of sufficient length
Test Procedure
Wrist Strap Test Using Integrated Checker
Integrated Checker
•
Place the wrist strap (with your personal ground cord attached) on wrist per your company’s
procedure. Adjust the cuff if necessary to ensure a snug fit.
•
Switch the wrist strap / footwear integrated checker to the wrist strap setting.
•
Insert/attach the loose end of the ground cord into the integrated checker.
•
With the hand on which the wrist strap is being worn, press and hold the metal contact / test
plate until the PASS / FAIL light illuminates and remains illuminated.
9
Wrist Straps
Compliance Verification
Wrist Strap Test Using Meter
Meter
•
Place the wrist strap (with your personal ground cord attached) on wrist per your company’s
procedure. Adjust the cuff if necessary to ensure a snug fit.
•
Attach the ground cord to the common terminal (-) of the meter.
•
Connect one end of the test lead to the hand-held electrode and connect the other end of the
test lead to the positive terminal (+) of the meter.
•
Hold the hand-held electrode with the hand on which the wrist strap is being worn.
•
Energize the meter using 10 volts.
•
Wait for the meter to stabilize.
•
Measure the resistance of the cuff and ground cord system.
•
When using a cloth cuff, it is recommended to periodically separate the buckle (metal portion
of the cuff) from the skin (measuring the continuity of the fabric) and perform this test.
Troubleshooting
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Examine the cuff to ensure that it is correctly sized and adjusted snugly to the skin.
•
Examine the cuff to ensure it is not soiled.
•
Replace the cuff with a new cuff and repeat the procedure.
•
Replace the ground cord with a new ground cord and repeat the procedure.
•
If the steps above are not effective, the person’s skin may have a high electrical resistance.
Changes in weather can affect the person’s skin contact resistance. Some cuffs have a
propensity to trap moisture underneath the cuff and can be more effective for people with dry
skin. The use of a skin lotion or gel compatible with process requirements may reduce the
person’s skin contact resistance. If skin lotions and gels are used, more frequent testing
during the work shift may be required to ensure their continued effectiveness.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
10
Constant Monitors
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ESD TR1.0-01-01, Survey of Constant (Continuous) Monitors for Wrist Straps
Objective
The objective of this periodic test procedure is to verify that the constant monitor is operating as
designed.
Constant monitors are designed to provide ongoing testing of the wrist strap system. While a
number of technologies are utilized, the goal remains consistent; electrical connections are tested
between the ground point, ground cord, wrist strap and body while the wearer handles ESD
sensitive items. Constant monitors may also provide a monitoring circuit for the ESD worksurface
connection to the ground reference.
Test Equipment
•
Compliance verification for the constant monitor should be performed to ensure that it is
properly functioning within its operating parameters.
•
Constant monitor functions can be verified at the workstation through verification instruments
available through the manufacturer of the constant monitor device.
Test Procedure
•
Compliance verification of the constant monitor device should follow the manufacturer’s
instructions.
Troubleshooting
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Follow the manufacturer’s recommendations for failed devices.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
11
Footwear
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ANSI/ESD STM9.1, Footwear – Resistive Characterization
•
ESD SP9.2, Footwear – Foot Grounders Resistive Characterization
•
ANSI/ESD STM97.1, Floor Materials and Footwear – Resistance Measurement in
Combination with a Person
Objective
The objective of this periodic test procedure is to verify the resistance of the footwear system
(person and footwear only) is within the minimum and maximum resistance allowed by the user's
specification. Footwear may consist of shoes, foot grounders and booties.
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
Integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring from 5.0 x 104 ohms to at least 1.0 x 1010 ohms with a test voltage
between 7 and 30 volts DC open circuit. Some integrated checkers require manual selection
to Footwear resistance test ranges.
•
Hand-held electrode
•
Foot electrode
•
Two test leads of sufficient length
Test Procedure
Integrated Checker
•
Place the ESD footwear on feet per your company’s procedure. If a body contacting
mechanism (conductive ribbon) is used with ESD footwear, place next to skin or sock.
•
Place one foot on the integrated checker’s foot electrode ensuring the other foot is not in
contact with foot electrode or adjacent ESD Flooring. Some integrated checkers may use a
dual-foot electrode to allow separate testing of each foot’s resistance.
•
Press the integrated checker’s contact plate with either hand until the PASS / FAIL light
illuminates and remains illuminated.
•
Repeat for other foot if necessary.
12
Footwear
Compliance Verification
Meter
•
Place the ESD footwear on feet per your company’s procedure. If a body contacting
mechanism (conductive ribbon) is used with ESD footwear, place next to skin or sock.
•
Connect one end of the first test lead to the hand-held electrode, and the other end of the first
test lead to the positive terminal (+) of the meter.
•
Connect one end of the second test lead to common terminal (-) of the meter, and the other
end of the second test lead to foot electrode.
•
Hold the hand-held electrode with either hand.
•
Place one foot on the foot electrode ensuring the other foot is not in contact with the foot
electrode or adjacent ESD flooring.
•
Energize the meter using 10 volts.
•
Wait for the meter to stabilize.
•
Measure the resistance of the ESD footwear system.
•
Repeat for other foot if necessary.
ESD Footwear Test Using Meter
13
Footwear
Compliance Verification
Troubleshooting
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Ensure ESD footwear is worn properly.
•
Examine the ESD footwear to ensure that its sole is not soiled or worn, which could add
resistance to the ESD footwear system. If necessary, clean the ESD footwear with an
approved cleaner and allow the ESD footwear to dry before retesting.
•
Changes in weather can affect the person’s skin contact resistance. The use of a skin lotion
or gel, compatible with process requirements, may reduce the person’s skin contact
resistance.
•
If necessary, replace the ESD footwear with new ESD footwear and repeat the procedure.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
14
Flooring
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ANSI/ESD S7.1, Floor Materials – Characterization of Materials
Objective
The objective of this periodic test procedure is to verify that the resistance of the ESD floor
system is within the minimum and maximum resistance allowed by the user's specification.
An ESD floor may consist of a permanently installed floor, floor with ESD floor finish, coatings,
paints or a mat.
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
Integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring at least 1.0 x 1010 ohms with a test voltage of 10 and 100 volts
(± 10%) DC open circuit.
•
One electrode
•
Two test leads of sufficient length
ESD Floor Test
15
Flooring
Compliance Verification
Test Procedure
Resistance Point-to-Ground
•
Do not clean the ESD floor immediately prior to verification.
•
Connect one end of the first test lead to the electrode, and the other end of the first test lead
to the integrated checker or meter.
•
Connect one end of the second test lead also to the integrated checker or meter, and the
other end of the second test lead to ground reference.
•
Place the electrode on the ESD floor surface and apply 10 volts.
•
Wait for the integrated checker or meter to stabilize.
•
If the indicated resistance is less than 1.0 x 106 ohms, continue testing.
•
If the indicated resistance is equal to or greater than 1.0 x 106 ohms, switch the integrated
checker or meter to 100 volts and retest the ESD floor.
•
Tests should include those ESD flooring areas that are subject to wear or are visibly dirty.
Troubleshooting
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Examine the ESD floor for excessive dirt / surface contamination. Remove surface
contamination at the test site by following manufacturer’s recommendations.
•
Examine the electrode for dirt buildup. Remove surface contamination by following the
manufacturer’s recommendations. If using liquids to clean electrode, allow the electrode to
dry before retesting.
•
Using an integrated checker or meter and two electrodes with test leads, perform a
resistance point-to-point test to verify the ESD floor material is the proper resistance.
•
When measuring ESD floor mats:
•
o
Check the connection of the mat fastener to the mat.
o
Check the connection of the ground cord to the mat fastener.
o
Check the connection of common point ground to the ground cord.
o
Check the connection of equipment ground to common point ground.
Both test leads should be capable of being isolated from ground. AC line powered resistance
measuring devices may give erroneous results due to undefined ground paths. Battery
powered equipment is recommended.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
16
Personnel Grounding with Garment
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ANSI/ESD S1.1, Wrist Straps
Objective
The objective of this periodic test procedure is to verify that the total series resistance of all of the
elements in the Personnel Grounding with Garment system is within the minimum and maximum
resistance allowed by the user's specification.
ESD garments may consist of clean room frocks, clean room cover-alls, lab coats, jackets and
smocks.
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
Integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring from 5.0 x 104 ohms to at least 1.0 x 1010 ohms with a test voltage
between 7 and 30 volts DC open circuit.
•
Hand-held electrode
•
Two test leads of sufficient length
•
Some integrated checkers require manual selection to Wrist Strap resistance test ranges.
Personnel Grounding with Garment Test
Using Integrated Checker
17
Personnel Grounding with Garment
Compliance Verification
Test Procedure
Integrated Checker
•
Put on a garment and properly snap or button it per your company’s procedure. Ensure the
cuffs are tight to the skin. If an adjustable cuff is used, adjust to ensure a snug fit.
•
Attach ground cord to the garment’s ground cord connection.
•
Switch the Wrist Strap / Footwear integrated checker to the Wrist Strap setting.
•
Insert/attach the loose end of the ground cord into the integrated checker.
•
Press and hold the metal contact / test plate with either hand until the PASS / FAIL light
illuminates and remains illuminated.
Meter
•
Put on a garment and properly snap or button it per your company’s procedure. Ensure the
cuffs are tight to the skin. If an adjustable cuff is used, adjust to ensure a snug fit.
•
Attach the ground cord to the garment’s ground cord connection.
•
Connect the loose end of the ground cord to the common terminal (-) of the meter.
•
Connect one end of the test lead to the hand-held electrode and connect the other end of the
test lead to the positive terminal (+) of the meter.
•
Hold the hand-held electrode with either hand.
•
Energize the meter using 10 volts.
•
Wait for the meter to stabilize.
•
Measure the resistance of the Personnel Grounding with Garment system.
Troubleshooting
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Examine the garment cuff to ensure that it is correctly sized and adjusted snugly to the skin.
•
Examine the garment and cuff area to ensure it is not soiled or torn.
•
If the steps above are not effective, the person’s skin may have a high electrical resistance.
Changes in weather can affect the person’s skin contact resistance. The use of a skin lotion
or gel compatible with process requirements may reduce the person’s skin contact resistance
around the cuff area. If skin lotions and gels are used, more frequent testing during the work
shift may be required to ensure their continued effectiveness.
•
Examine the seams between panels to ensure they are not soiled or torn.
•
Replace the old ground cord with a new ground cord and repeat the procedure.
•
Replace the garment with a new garment and repeat the procedure.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
18
Garments
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ANSI/ESD STM2.1, Garments
Objective
The objective of this periodic test procedure is to verify that the sleeve-to-sleeve (or cuff-to-cuff)
resistance of garments is within the minimum and maximum resistance allowed by the user's
specification.
ESD garments may consist of clean room frocks, clean room coveralls, lab coats, jackets and
smocks.
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
Integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring at least 1.0 x 1012 ohms with a test voltage of 100 volts
(± 10%) DC open circuit.
•
Two electrodes
•
Two test leads of sufficient length
•
Insulative support surface
Garment (Sleeve-to-Sleeve) Test
19
Garments
Compliance Verification
Test Procedure
•
Connect the two electrodes to the test leads and connect the test leads to the integrated
checker or meter.
•
Place the garment on the insulative support surface.
•
Set the electrodes on each sleeve (or each cuff) of the garment. Ensure the sleeves are
separated from the body of the garment.
•
Apply 100 volts to the garment under test.
•
Wait for the integrated checker or meter to stabilize.
•
Measure the resistance of the garment.
Troubleshooting
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Examine the electrodes for dirt buildup. Remove surface contamination by following the
manufacturer’s recommendations. If using liquids to clean electrodes, allow to the electrodes
to dry before retesting.
•
Examine the garment (e.g., seams between panels) to ensure it is not soiled or torn.
•
Review laundry process:
o
High temperatures from washing, drying or ironing may damage the carbon fibers in
the garment.
o
Fabric softeners used in the laundry process may coat the fibers.
o
Chlorine bleach may damage conductive fibers (especially silver based fibers).
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
20
Air Ionizers
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ANSI/ESD STM3.1, Ionization
•
ESD SP3.3, Periodic Verification of Air Ionizers
Objective
The objective of this periodic test procedure is to verify that the discharge time and offset voltage
(ion balance) of air ionizers is in compliance with the user's specification.
The test steps in this periodic test procedure are common for the following classes of ionizers:
room, laminar flow hood, worksurface and automated equipment (bench top and overhead), and
compressed gas (gun or nozzle).
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
A CPM (as specified in ANSI/ESD STM3.1) or a portable verification kit (as specified in ESD
SP3.3).
•
A stopwatch or other suitable means is typically used to measure discharge time with
portable verification kits.
•
A measuring tape or ruler.
Test Procedure
Initial Test Setup
•
Measurements should be made at the location where ESD sensitive items are to be ionized.
•
Air ionizer heaters and air filters (if so equipped) should be left in their normal conditions
during test.
Discharge Time Test
•
Turn the test equipment on and allow it to stabilize per the manufacturer’s recommendations.
•
Momentarily ground the plate and set (or verify) zero voltage.
•
Do not zero (or charge) the portable verification instrument in the presence of the ion field.
•
Charge the test plate to a convenient voltage in excess of the initial test voltage for each
polarity (e.g., 1200 to 1500 volts).
•
Ensure the test plate is facing the air ionizer’s airflow.
•
The discharge time measurement begins when the test plate voltage has decayed to the
initial test voltage (e.g., 1000 volts) and stops when the test plate voltage has decayed to the
final test voltage (e.g., 100 volts).
•
Repeat steps above for the opposite polarity.
•
Note the discharge time in seconds for each polarity.
21
Air Ionizers
Compliance Verification
Offset Voltage Test (Balance)
•
Turn the test equipment on and allow it to stabilize per the manufacturer’s recommendations.
•
Momentarily ground the plate and set (or verify) zero voltage.
•
Do not zero the portable verification instrument in the presence of the ion field.
•
Place the test plate facing the air ionizer’s airflow.
•
Wait for a user-specified period of time.
•
Note the offset voltage (balance).
Troubleshooting
Discharge Time and Offset Voltage Test Failures
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Check that the test equipment is properly grounded.
•
Check that there are no large conductive objects in the area that could cause ion attraction to
their surface.
•
Check that items in the work area are not blocking the airflow.
•
Check fans for proper operation.
•
Check air filters for clogging with dust and dirt. Clean or replace air filter as necessary.
•
Check emitter points (they should be clean and not bent or broken). Clean or replace if
necessary, following the manufacturer’s instructions. Allow emitter points to dry before
retesting.
•
Check electrical equipment grounds for grounding integrity.
•
If applicable, adjust the offset voltage of the ionizer following the manufacturer’s instructions.
•
Check alpha sources for service life date. Replace if necessary, following the manufacturer’s
instructions.
•
Check the alpha cassette to ensure it is properly grounded per the manufacturer’s
instructions.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
22
Seating
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ANSI/ESD STM12.1, Seating – Resistive Measurement
Objective:
The objective of this periodic test procedure is to verify the resistance of the ESD chair grounding
system (chair through grounded ESD floor) is within the minimum and maximum resistance
allowed by the user's specification.
Test Equipment:
•
Reference the Test Equipment section in the beginning of this document.
•
An integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring at least 1.0 x 1010 ohms with a test voltage of 10 and 100 volts
(± 10%) DC open circuit.
•
One electrode
•
Two test leads of sufficient length
ESD Chair Test
23
Seating
Compliance Verification
Test Procedure
•
Place the ESD protective chair on an installed ESD floor.
immediately prior to verification.
•
Connect one end of the first test lead to the electrode and connect the other end of the first
test lead to the integrated checker or meter.
•
Connect one end of the second test lead also to the integrated checker or meter and connect
the other end of the second test lead to ground reference.
•
Place / hold the electrode on the following areas of the chair (center the electrode on any
worn areas) and apply 10 volts:
o Center of the seat panel
o Center of the seat back
o Foot ring (if so equipped)
•
Wait for the integrated checker or meter to stabilize.
•
If the indicated resistance is less than 1.0 x 106 ohms, continue testing.
•
If the indicated resistance is equal to or greater than 1.0 x 106 ohms, switch the integrated
checker or meter to 100 volts and retest the ESD chair.
•
Tests should include those areas on the ESD chair that are subject to wear or are visibly
dirty.
Do not clean the ESD floor
Troubleshooting
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Examine the electrode for dirt buildup. Remove surface contamination by following the
manufacturer’s recommendations. If using liquids to clean electrode, allow to the electrode to
dry before retesting.
•
Clean the wheels / casters with approved cleaner. Allow the wheels / casters to dry before
retesting.
•
Verify the resistance of the ESD floor surface to reference ground. If the ESD flooring
surface resistance is high, clean the floor with an approved cleaner. Allow the floor to dry
before retesting. If the floor passes after cleaning, retest the chair. If the floor fails, go to
Troubleshooting in the Flooring section.
•
Verify that the resistances of the chair’s components have an appropriate resistance using
two electrodes (point-to-point resistance testing). This testing will help isolate a defective
component (or connection between the chair’s components).
•
Clean / vacuum the cloth seat, or clean the vinyl seat with an approved cleaner (allow the
vinyl to dry) and retest.
•
When holding the electrode, ensure you are not a path of lesser resistance to ground. The
electrode should be insulated from the operator by a resistance greater than 1.0 x 1010 ohms
when measured at 100 volts. This may be accomplished by using either an insulative sleeve
over the electrode or body, or by the operator using an insulative glove or similar material.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
24
Mobile Equipment (Carts)
Compliance Verification
This periodic test procedure is in part, based on the following publication(s):
•
ANSI/ESD S6.1, Grounding – Recommended Practice
•
ESD ADV53.1, ESD Protective Workstations
•
ANSI/ESD S4.1, Worksurfaces – Resistance Measurements
Objective:
The objective of this periodic test procedure is to verify the resistance of the cart grounding
system (cart through grounded floor) is within the minimum and maximum resistance allowed by
the user's specification.
Carts that are grounded with a ground cord (and are not grounded through an ESD floor) should
be tested according to the Worksurfaces section of this document.
Test Equipment
•
Reference the Test Equipment section in the beginning of this document.
•
Integrated checker or meter, whether it is a single meter or a collection of instruments that
are capable of measuring at least 1.0 x 1010 ohms with a test voltage of 10 and 100 volts
(± 10%) DC open circuit.
•
Electrode
•
Two test leads of sufficient length
CL
CL
ESD Cart Test
25
Mobile Equipment (Carts)
Compliance Verification
Test Procedure
•
Place the cart on a grounded ESD protective floor.
•
Do not clean the ESD floor immediately prior to verification.
•
Remove all ESD sensitive items from the cart.
•
Connect one end of the first test lead to the electrode, and the other end of the first test lead
to the integrated checker or meter.
•
Connect one end of the second test lead also to the integrated checker or meter, and the
other end of the second test lead to ground reference.
•
Place the electrode on the center of the top shelf of the cart and apply 10 volts.
•
Wait for the integrated checker or meter to stabilize.
•
If the indicated resistance is less than 1.0 x 106 ohms, continue testing the remaining shelves
on the cart.
•
If the indicated resistance is equal to or greater than 1.0 x 106 ohms, switch the integrated
checker or meter to 100 volts and repeat test for other shelves on the cart.
•
Tests should include those areas on the cart that are subject to wear or are visibly dirty.
Troubleshooting
•
Verify the test equipment is operating properly, check / service the battery (if battery
operated), following the manufacturer’s operating instructions for proper operation.
•
Visually check to ensure that the casters or contact point used to ground the cart to the floor
are not soiled and attached securely (clean accordingly, if necessary).
•
Examine the cart’s shelf grounding connections.
•
Examine the conductive casters or the contact point (if used) on the cart to ensure that they
are not soiled or worn, which could add resistance to the cart grounding system. If soiled,
clean the conductive casters on the cart with an approved cleaner (water or IPA for example),
and repeat the procedure.
•
Examine the electrode for dirt buildup. Remove surface contamination by following the
manufacturer’s recommendations. If using liquids to clean electrode, allow to the electrode to
dry before retesting.
Defective ESD equipment and materials that cannot be brought into compliance should be
removed from the ESD Protected Area.
26
Packaging
Compliance Verification
The test procedures referenced in ANSI/ESD S541 (Packaging Materials for ESD Sensitive
Items) can be used to periodically verify packaging materials. Due to the wide variety of
packaging materials in use, the users should develop their own compliance verification plan for
packaging.
27
ANNEX A
Test Frequency
The objective of the periodic test procedures listed in this document is to identify if significant
changes in ESD equipment and materials performance have occurred over time.
Test frequency limits are not listed in this document, as each user will need to develop their own
set of test frequencies based on the critical nature of those ESD sensitive items handled and the
risk of failure for the ESD protective equipment and materials.
Examples of how test frequencies are considered:
•
Daily wrist strap checks are sufficient in some applications, where in other operations
constant wrist strap monitoring may be used for added operator grounding reliability.
•
Packaging checks may depend on the composition of the packaging and its use. Some
packaging may have static control properties that deteriorate more quickly with time and use
and some packaging may be humidity dependent and may have limited shelf life.
•
Some materials, such as ESD floor finishes, may require more frequent monitoring because
of their lack of permanency. Other materials, such as ESD vinyl floor covering, may require
less monitoring. The testing of a floor should also be considered after maintenance on the
floor has been performed.
28