[vcf-midatlantic] anti-static carpet

Chris chrisjpf33 at gmail.com
Sat Feb 6 08:51:55 EST 2016

On Feb 6, 2016, at 7:41 AM, Dan Roganti via vcf-midatlantic<vcf-midatlantic at lists.vintagecomputerfederation.org> wrote:

This is only half of the solution.
Shoes are not conductive when it involves ESD, so
The anti-static carpet only works on one condition  - as they are meant to
provide discharge path, so
1. If you are wearing anti-static boot straps - as in a Lab --- I doubt the
visitors have this
2. wearing ESD conductive shoes ---> again, I doubt the visitors will have

You like to have the person discharged before you ever enter the room.
As you don't know how much charge they might have, you can have 100,000ev
without even knowing it.
Even if you had just concrete, they can still be charged coming from some
other part of InfoAge
Especially when they have ordinary carpet elsewhere -- remember the door
knob jolt.
And it's .more. prevalent when the humidity is very low - as in the winter,
or in super cold A/C.
It's nice to have a climate-controlled environment but it's not always
As you have a need for all 4 systems, A/C, Heater, Humidifier, and
All combinations in the environment can exist, cold/dry, cold/wet, hot/dry,
or hot/wet.

The quickest way is to build a simple ESD Grounding station at the entrance.
All it takes is,
1. a 1meg ohm resistor -- to slowly bleed off the ESD - no jolts
2. some metal [eg. door knob] that is isolated -- something plastic, eg,
3. and then wired to earth ground.

Then you don't get the zaps or jolts when touching this to discharge
yourself - as on a typical door knob.
The have some kind of sign, such as, "Keep Computers Safe, Get Rid of
Static, Please Discharge" with an arrow pointing to that.

Dan is correct on all counts. Thanks for sharing! May I add that there is a difference between anti-static and conductive.

In an ideal electronics work environment, things are conductive so that all static charges are quickly dissipated safely and never have a chance to discharge destructively through the equipment. Also, the conductivity is limited with a resistance, either added or inherent in the material, so that the discharge happens gently and not abruptly. In a lot of cases, conductive clothing (lab coat woven with conductive fibers) is also worn so that static fields don't damage equipment when they are in proximity to equipment. Contact is not necessary to cause a destructive discharge.

Anti-static means that the materials are formulated so that they aren't contributors to causing a static charge buildup. They won't necessarily discharge a static charge, but the won't exacerbate the situation by acting like an insulator and holding a charge.

I think that in our situation, we can't control the clothing that people are wearing, so it will never be an ideal situation. We just need to create an environment that isn't making the situation worse. No wool carpet or plexiglass panels. And limit visitors' contact with and proximity to sensitive equipment.


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