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ESD
Journal Approved Tests Method
ATP Triboelectric T-1000 March 11, 2003 "SHOE SHINE" STATIC TEST The Naval Weapons Laboratory used this test as early as the 1960's for evaluation of garments used in electrostatically sensitive areas, especially in the handling of primary explosives. It has been used by Brunswick for the development of upholstery fabrics and is now used by at least two ESD Labs for testing of fabrics and garments: Fowler Associates and K&S Labs. This tests method is intended to determine the potential on a person wearing garments made from various fabrics who has been rubbed across the person's back with the material under test. Variations of this test may include the subject wearing a test garment and being rubbed by a various range of fabrics. This test method may also be used to determine the potential on a test material when rubbed on a test subjects clothed back. Procedure: This test method requires two technicians: an operator and a test subject. The operator folds a "scarf" of rubbing material to a size of about 5' long by 5" wide.
The
test subject grounds himself and the operator neutralizes any surface
charges from the test subject's back, tests materials and soles of the
test subject's shoes. The feet of the test subject must be kept still
during the test. The operator grasps the scarf near the ends, first ionizing it to remove any residual charges from handling. The operator then smartly strokes the upper back of the test subject five times in the manner of a shoe shine rag polishing a shoe. After the last stroke, the operator quickly steps back away from the test subject to a distance of three to five feet to exclude the effect of the field coming from the scarf. The criterion of static is the maximum body potential on the test subject. While
this test was originally used to qualify personnel garments, it is equally
useful in measuring the performance of, for example, upholstery material,
in which case various upholstery scarves are used against various clothing
or draped cloth materials. Some suggested clothing and seat materials
may include; Denim, Linen, Silk, Rayon, Wool, Rayon/PE, Cotton & Polyester
The additional measurement of the potential on the scarf material may also yield useful information. This may be accomplished with or without the operator wearing gloves for isolation of the scarf material. For this measurement, the scarf material is immediately after the strokes, held in front of a non contacting volt meter and the volts/inch recorded. These
tests are intended to be carried out at 12% RH, 720 F after 72 hours
of conditioning at these conditions.
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The
test subject stands on any insulative surface ( greater than 1E13 Ohms)
and holds a lead or wears a wrist strap with no resistor which connects
to a suitable high impedance recording volt meter, e.g., a charged plate
monitor.
Quantitative
indexing is a little difficult due to the wide variations in the way
that people slide and stand up, differences in shoes and floor coverings,
etc. However, the maximum voltage achieved in this test is an excellent
ranking parameter and can be tailored to closely approximate worst-case
real life conditions.