Approved Test Procedures - ATP # G1000/August
1998
Gloves
1. Purpose
1.1 The purpose of this test procedure is to determine the electrical
resistance and relative static charging propensity of gloves used
for ESD control applications.
1.2 It is not the purpose of this test procedure to set standards
of acceptance.
2. Scope
This test procedure is intended for use with gloves of all construction
and materials.
3. Principle
3.1 The beneficial contribution of electrical conductivity to the
dissipation of static charges generated by persons using gloves in
ESD control work functions has long been recognized. Gloves with reasonable
conductivity across the surface and to the hand help keep static charges
to a minimum. However, conductivity is not sufficient to characterize
the ESD performance of a glove for work with all products and materials.
3.2 When gloves have a reasonable conductivity they typically will
keep to a minimum the static charges on conductive materials which
are being handled. When insulative materials such as plastic IC packages
and fiberglass substrates are handled, many gloves - even though conductive
- impart high static charges through triboelectric effects.
3.3 This test procedure characterizes gloves for their electrostatic
effects on most products.
4. Safety Precautions
4.1 Note: these safety precautions are for information purposes only.
The precautions are ancillary to the testing procedures and are not
intended to be all inclusive. It is the users responsibility to use
safe and proper techniques in handling materials in this test method.
Manufacturers MUST be consulted for specific details such as material
safety data sheets and other manufacturers recommendations. All OSHA
standards and rules must also be consulted and followed.
4.2 Where electrical instrumentation is required, all manufacturers'
recommendations for safety must be adhered to as well as all applicable
electrical codes of practice. If test personnel are not familiar with
safety precautions, a competent electrical technician or electrician
must be consulted.
5. Apparatus and Materials
5.1 Test area: Standard test conditions for this test method
require a room or large enclosure which can be maintained at 22 +/-
2 C and at a relative humidity of 12 +/- 3 % and suitable means for
monitoring these conditions. Special requirements of end use may dictate
the use of other testing conditions. Audit measurements shall be at
the recorded ambient conditions during the tests.
5.2 Ohmmeter: Electrical resistance measurement instrumentation
capable of reading the expected range of resistances. Typically this
range for static protective gloves should be between 10 kilo Ohms
and 100 Gig Ohms. The electrical resistance measuring instrument should
have a regulated output voltage capability of ten (10) to 100 volts.
Ten (10) volts should be used for more conductive gloves and 100 volts
for the more resistive gloves.
5.3 Resistance Electrodes: Two cylindrical 2.3 kg metal electrodes
with a diameter of 63.5 mm each having contacts of electrically conductive
elastomeric material with a thickness of approximately 6.35 mm and
Shore-A (IRHD) durometer hardness of approximately 50. The resistance
between the two electrodes should be less than 100 k Ohms when measured
at 10 volts on a conductive metal surface. Standard electrodes constructed
in accordance with NFPA 99 and ASTM F-150 may be modified to achieve
these characteristics. A surface that has a point-to-point resistance
of greater than 1.0 Tera Ohms shall be used as the specimen support
surface for all resistance measurements except those involving the
human hand.
5.4 Charged Plate Monitor: The charged plate monitor shall
have an aluminum plate approximately 7 cm by 12 cm with a total capacitance
of approximately 15 picofarads. The charged plate monitor shall be
capable of measuring 2,000 volts, +/- 10%.
5.5 Faraday Cup & Coulomb Meter: The Coulomb meter shall
be capable of measuring 200 nano Coulombs, +/- 10%. The Faraday cup
shall be able to receive the specimen under test inside the cup with
a minimum of 25 mm distance to the top of the cup.
5.6 Triboelectric Test Material: For this procedure the material
chosen to represent the tribocharging propensity for gloves is a 26
mm X 26 mm BGA (ball grid array) IC which is composed of an epoxy
IC package on a fiberglass and metal contact substrate. Special requirements
may dictate the use of other materials.
5.7 Wrist Strap: A standard fabric style wrist strap connected
directly to the resistance measurement instrument.
5.8 Air Ionizer: A forced air high voltage ionizer with an
imbalance of less than +/- 1 volt.
6. Test Specimens
A minimum of 6 glove samples should be tested after being chosen
by a valid sampling procedure.
7. Conditioning of Specimens
7.1 All test gloves shall be preconditioned at 22 +/- 2 C and at
a relative humidity of 12 +/- 3% for a period of at least 48 hours.
7.2 Gloves being audited while in use may tested at ambient conditions.
8. Test Procedures
8.1 Resistance - Palm to Fingers
8.1a Place the glove under test on the insulative support. Position
one electrode on the inside palm portion of the glove and the other
electrode on the thumb of the glove.
8.1b Record the resistance reading.
8.1c Leaving the first electrode on the palm of the glove reposition
the second electrode on each finger of the glove separately. Record
the resistance readings of each finger.
8.1d Repeat the above procedure for all six glove specimens.
8.2 Resistance - Finger to Body
8.2a This test procedure shall be measured at 10 volts.
8.2b Place the glove under test on the technician's hand of preference.
Attach the ungrounded wrist strap to the wrist of the gloved hand.
Attach a wrist strap lead to the resistance meter. Make sure the wrist
strap makes a good connection with the skin. Lotions may be used to
assure good connection. Do not contaminate the glove with the wrist
lotion.
8.2c Attach one electrode to the other terminal of the resistance
meter. Press the index finger of the gloved hand against the conductive
rubber of the electrode.
8.2d Record the resistance reading between the electrode being touched
by the gloved hand and the wrist.
8.2e Repeat the above procedure for all five fingers.
8.2e Repeat the above procedure for all six glove specimens.
8.3 Resistance - Palm to Body
8.3a This test procedure shall be measured at 10 volts.
8.3b Place the glove under test on the technician's hand of preference.
Attach the ungrounded wrist strap to the wrist of the gloved hand.
Attach a wrist strap lead to the resistance meter. Make sure the wrist
strap makes a good connection with the skin. Lotions may be used to
assure good connection. Do not contaminate the glove with the wrist
lotion
8.3c Attach one electrode to the other terminal of the resistance
meter. Pick up and grasp the electrode with the gloved hand.
8.3d Record the resistance reading between the electrode being grasped
by the gloved hand and the wrist.
8.3e Repeat the above procedure for all six glove specimens.
8.4 Triboelectric Charge Generation - Charged Plate
8.4a Place the glove under test on the technician's hand of preference.
Attach the grounded wrist strap to the wrist of the gloved hand. Make
sure the wrist strap makes a good connection with the skin. Lotions
may be used to assure good connection. Do not contaminate the glove
with the wrist lotion.
8.4b With the gloved hand stroke the aluminum plate vigorously five
(5) times without lifting the gloved hand and as the last stroke is
complete, extremely quickly remove the gloved hand from the aluminum
plate.
8.4c Record the voltage readings.
8.4d Repeat the above procedure for all six glove specimens.
8.5 Triboelectric Charge Generation - Faraday Cup
8.5a Place the glove under test on the technician's hand of preference.
Attach the grounded wrist strap to the wrist of the gloved hand. Make
sure the wrist strap makes a good connection with the skin. Lotions
may be used to assure good connection. Do not contaminate the glove
with the wrist lotion.
8.5b Clean the BGA triboelectric sample with Isopropyl alcohol. Dry
the BGA sample and gloved hand under the air stream of the air ionizer.
Zero the Faraday cup.
8.5c With the gloved hand hold the BGA sample between the thumb and
forefinger. Rub the BGA sample five (5) times with the thumb and forefinger
and as the last rub is complete, quickly drop the BGA sample into
the Faraday cup.
8.5d Record the Coulomb readings.
8.5e Repeat the above procedures for all six glove specimens. Neutralize
the BGA sample and gloved hand under the air stream of the ionizer
between each test.
9. Audit Test Procedures
The above tests may be performed on gloves in use in the field under
the ambient conditions of the work areas. The results may of course
be only used as a comparison since the ambient conditions may be favorable
or not to any particular style of glove.
10. Report of Data
- Report all readings .
- Report the average of all sets of readings.
- Report the date, time, humidity and temperature of the tests.
