Fowler Associates Labs

IronAge

Chip-Tec
Makes the
"MEG OHM" Shoe Possible

By: Jennifer Hazen, Editor
January 17, 2003

Steve Fowler coauthored a paper in 1997 at the ESD Symposium on flooring and footwear (click here for paper). In that paper he, Bill Klein and Larry Fromm discussed what a perfect ESD shoe would be. Again in a later article on Meir Golane's symposium paper, Steve Fowler and Meir Golane discussed the properties of the perfect ESD shoe.(click here for paper). In these discussions the resistance through the shoe was considered very important (along with the sole resistance). The problem many shoes have is the ability to have a repeatable resistance in the "sweet" range of "a Meg Ohm." The "Meg Ohm" range has come to mean any resistance through the person to a metal plate of 1 - 9.99 Meg Ohms. If the shoe/ floor resistance is to be no greater than 35 Meg Ohms according to ESD S20.20, then the resistance of the shoe must be as repeatable in that "sweet" range as possible.

How does a shoe manufacturer make the "Meg Ohm" shoe and make it a Meg Ohm each time? That was the question haunting the shoe companies for decades. Shoes are made up of many layers, compounds, materials, etc. Each of which have their own variability which usually makes the total resistance of a shoe unable to be controlled tightly. Many manufacturers will state that their ESD shoes are "below 100 MegOhms." That is because the nature of the shoe manufacturing process tends to only allow an upper limit not a controllable range.

Ironage has developed their Chip -Tec ESD Shoe using a flexible circuit to connect the inside of the shoe to the bottom of the shoe. Just like the resistor of a wrist strap makes the value of that connection very repeatable at 1 Meg Ohm., the new Chip-Tec circuit allows the Ironage ESD shoes to have a resistance to ground according to ESD STM 97.1 of a "Meg Ohm." That makes them quite different in the world of shoes. Ironage has brought the art of manufacturing ESD into the 21st Century with the "Meg Ohm" shoe.

The shoes come in a varity of styles.

*Ironage and Chip-tec are trademarks of the Ironage Corporation