ESD discharge for office - Page 1
Forum section: electronics / beginners

author: brainwash
author_rank: Frequent Contributor
timestamp: June 10, 2017, 09:00:46 pm
content: My small home office is mostly set up for comfort: an "executive" rolling chair, two desks. one for IT stuff, one for electronics. The easiest way to get by is to roll from one to another (~1m). I use house slippers/crocs (convenience), have a rug, the chair is textile covered, I don't work naked. This means that static builds up all the time, especially when I get up from the chair. It's the kind of shocking static.My current approach is to take out one slipper and touch the floor before handling any electronics. Or touch the ESD strap, which is too short/inconvenient to have on all the time.Looking for a way to have a better 'automatic' handling of this problem. Perhaps needle a small bent copper wire through the slipper? Have a sort of copper/brass brush on the chair that touches the ground? Use an ESD mat instead of a mouse pad? I have no ideea what works and what not and what other people use in non-professional offices.I haven't killed any component yet, but want to avoid having to remember to touch grounded screws all the time.

author: BrianHG
author_rank: Super Contributor
timestamp: June 10, 2017, 09:09:07 pm
content: If your situation allows it, you can always use high humidity. In my older setup, especially for our dry winters here in Montreal, I had a super large humidifier always running & kept the relative humidity between 45% & 50%, where all static vanished.It was like a tropical forest in the office, also great for dry skin.

author: brainwash
author_rank: Frequent Contributor
timestamp: June 10, 2017, 09:14:35 pm
content: My SOHO already has 40+% (usually 60%) humidity, I think it's just the choice of materials that makes it worse.I've heard some stories from lower/south US where production chips get killed just by looking at them (exaggeration, of course). But there you have a hot, dry, sand-particle-loaded wind that requires every measure you can take.

author: X
author_rank: Regular Contributor
timestamp: June 10, 2017, 09:20:07 pm
content: A negative ion generator may be useful. I think these are used in some datacenters and anti-static workspaces.

author: brainwash
author_rank: Frequent Contributor
timestamp: June 10, 2017, 09:21:13 pm
content: I wanted to buy one for the dust. But don't those promote rusting?

author: X
author_rank: Regular Contributor
timestamp: June 10, 2017, 09:29:02 pm
content: I've never experienced or heard of this with negative ion generators, but ozone generators can promote degradation of some rubbers and plastics. Perhaps the promotion of rust you heard about is for ozone generators.

author: brainwash
author_rank: Frequent Contributor
timestamp: June 10, 2017, 09:55:55 pm
content: That's interesting, I've never heard of that concept before, just the usual 'fresh air' generators. Everyone is complaining (on Amazon) that everything around them rusts. There's a wikipedia article on it, but are there real cases where this has been used?However, I'm not sure if that would apply in my case. The static charge built up from getting from a chair is very sudden, while I expect the generators to take at least 10 minutes to dissipate the charge. Not making judgements, just asking questions.

author: tooki
author_rank: Super Contributor
timestamp: June 12, 2017, 02:35:58 pm
content: Quote from: brainwash on June 10, 2017, 09:14:35 pmIn the Southwestyeah. But the entire east coast and Gulf coast areextremelyhumid much of the year. Mississippi is the most "Deep South" place, and it's spectacularly humid.

author: tooki
author_rank: Super Contributor
timestamp: June 12, 2017, 02:43:31 pm
content: Quote from: brainwash on June 10, 2017, 09:00:46 pmLook at the ESD safety sections of catalogs from electronics vendors and workplace equipment vendors. They'll have ESD chairs, slippers, etc etc etc. But you could probably achieve a lot by using ESD spray (they sell versions for carpet and textiles, and for hard surfaces) which helps charges to dissipate. A metal chain would work better than a brush to hang from the bottom of the chair. I'd put an ESD mat on the entire desk. And work barefoot instead of the crocs.They sell conductive straps and things to retrofit footwear, but dedicated ESD slippers might work better.If you can ditch the rug, you really should. If not, use the spray.Don't worry about everything being copper; low resistance isn't desired. Remember that everything that's grounded for ESD safety should be grounded via a 1M+ resistor for safety.

author: David Hess
author_rank: Super Contributor
timestamp: June 12, 2017, 07:31:44 pm
content: I would start with an ESD air ionizer and then work back to changing the chair and your foot coverings if necessary.

author: mdszy
author_rank: Unknown
timestamp: June 12, 2017, 07:34:04 pm
content: ESD Heel strap? They strap to your shoe and go inside by your sock and allow you to discharge to earth. We use those at work and they work pretty well.

author: floobydust
author_rank: Super Contributor
timestamp: June 12, 2017, 08:25:26 pm
content: In Canada ESD is pretty bad in winter.I spray fabric softener (diluted with water) like Downy on carpets/chairs. That stops "static cling" on clothes they say, stops triboelectricity somehow.At home I use anti-static chair mat and a desk mat really helps- but when you get up and leave your chair, you have high charge.Home ion generators are bad, they add charge to the air that accumulates on things (negative ion generators)ESD air deionizers are pretty expensive.

author: BrianHG
author_rank: Super Contributor
timestamp: June 12, 2017, 08:36:15 pm
content: Quote from: BrianHG on June 10, 2017, 09:09:07 pmI made a mistake, I keep my lab at 65% to 75% relative humidity (checked the lines I drew on my humidity meter which I labeled electronic-safe-zone). Almost no static at all under these circumstances.Here in the winter in Canada, the worst being January through March, I have to fill my humidifier with at least 12 liters of water/day to maintain this level of tropical humidity.From the absurd humidity, my windows get covered with a sheet of ice on the really cold days.When I used to go to the local Future Active Industrial electronics warehouse, they also had both heavy duty humidifiers and 4 water mist sprayers at the top of every support beam pointing in 4 directions running 24/7.

author: brainwash
author_rank: Frequent Contributor
timestamp: June 12, 2017, 08:39:47 pm
content: Thanks everyone for the replies, still waiting for feedback.As a clarification: the chair cannot be exchanged, for now. The rug rarely makes contact with the chair, it's just there for looks and as a dust trap. The floors are PVC covered, those come with the building, cannot change them (as a tenant) without significant expense. They are grounded (electrical floor heating) but they still build up charge on the things that are on top of them.Most of the static is generating when getting up from the chair. Humidity is always 40%+. In the winter is even higher (around 70%).A wrist (hand or foot) strap can be added, but it's too inconvenient in everyday usage, as I have to get up a lot.Other than that, I take all necessary precautions when handling electronics stuff. However, I do have visitors that sit on my chair and build up charge. I dislike having to tell everyone to discharge and 'take a shock for the good of mankind' before touching ESD-sensitive stuff.However, I will slowly implement all of the measures mentioned so far, hope they mitigate some of the potential problems.Questions on the suggestions so far:Still not sure on the ion generator gadgets: how would one look for them on amazon or something similar? Do they really do something?Anyone tried adding a dissipative brush/chain to an office chair? I have the suspicion that would work the best.Do humidifiers add dangerous conductive salts? Do they dissipate just humidity without salts? Or are they supposed to be used with distilled water?

author: BrianHG
author_rank: Super Contributor
timestamp: June 12, 2017, 08:51:09 pm
content: Get a heavy duty wick based humidifier. You will just need to replace the wick once a year it you run it almost 24/7 like me.The sponge based humidifiers are only for furnaces and require hot air to work.The ultrasonic mist humidifiers will put most of whatever is in your tap water into you air and may not be good for continuous use or add calcium carbonate to the surface of your electronics. With the wick based devices, most of these impurities just build up in the wick and don't make it into the air, this is why the wick eventually needs replacement. The wick is an evaporation process, so the humidity is really clean and close to natural.The reason why you need a big unit, get the cheap 25-45$ with 2 huge 8 liter removable water tanks, is the large diameter of the largest possible wick with a large diameter fan is needed to push the humidity to the max.

author: brainwash
author_rank: Frequent Contributor
timestamp: June 12, 2017, 08:56:37 pm
content: I know only of the evaporative one (hot resistance in water) and evaporative one (fan blowing on water). Not sure if I got those right, not a native English speaker. Which one is wicked and which one is the other one? Perhaps some example would help.

author: BrianHG
author_rank: Super Contributor
timestamp: June 12, 2017, 09:23:04 pm
content: Yes, the fan blowing in water through a circular wick. A white like filter. The humidifier I have is similar to those that hold 9 gallons of water in it's tank, except it's an older 2 tank one which held 18 gallons, but it is discontinued.Similar to this:https://www.amazon.com/Lasko-1128-Evaporative-Recirculating-Humidifier/dp/B00FGLPCN8/ref=sr_1_1?ie=UTF8&qid=1497302224&sr=8-1&keywords=9+gallon+humidifierUses a wick like this:https://www.amazon.com/Honeywell-HAC-504AW-Humidifier-Replacement-Filter/dp/B000RDAORO/ref=sr_1_3?ie=UTF8&qid=1497302322&sr=8-3&keywords=humidifier%2Bfilter&th=1I'm surprised you never heard of ultrasonic. Those are the cheap thing that produce a visible mist coming out of the humidifier and they have no replacement filters or fans.Furnaces and heaters use the sponge, or, metallic type looking filter type humidifier, but once again, these only come in heaters or furnaces and only work when the heat is on.

author: David Hess
author_rank: Super Contributor
timestamp: June 12, 2017, 09:31:55 pm
content: An ultrasonic dehumidifier could be filled with distilled or maybe reverse osmosis water.Search for "esd air ionizer". As floobydust says, they are not cheap but maybe you can find a used one. If you are worried about ESD, then you really should be using one on your workbench anyway.