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I traveled by plane for the first time in my life 3 months ago. It was 4 trips, which meant 4 hand luggage inspections.

I have a huge problem: I was asked to remove my laptop and tablet from my bag and place them alone on a separate plastic tray. While they pass through the X-ray machine, I pass through the metal detector. However, when I go back and grab my laptop, I get the living s**t zapped out of me.

I did it twice (in 2 different airports with very different security devices) and it happened every time. My brother did it once and it did not happen to him. Likewise for my mother. The sound is so loud, people turn to look at me. And it's so painful to me, I involuntarily jump backwards. The spark is clearly visible but there is no burn mark or anything like that on my hand or my laptop's paint. My laptop has a stretched aluminum case painted in black (more specifically, Lenovo IdeaPad y510p).

Touching the tablet after the laptop has no effect. I never touched it before the laptop because experimenting was the last thing on my mind at the time. My best idea is to wear gloves when handling my laptop, but I fear two things: 1. I'll look suspicious and only end up wasting everyone's time going through checks and what-not. 2. If I don't discharge the laptop, it will discharge on something else, possibly doing damage, or worse, zap me later at a perhaps more inappropriate time.

I touched more metallic objects before my laptop, such as the edge of the thread that moves the bags and my belt.

Could you suggest a solution or a workaround for this issue? Next time I travel, I will have to take 3 laptops with me, 2 of which have metal casings...

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    Have you tried touching the metallic frame of the X-Ray machine? Secondly it seems more likely that the static electricity builds on you rather then on the laptop. May be you need to change what you wear...
    – Karlson
    Jun 12, 2014 at 16:48
  • I haven't, and, if my memory serves me well, it was well out of reach in every situation. However, as I mention in the question, I touched the metallic edge of the thread which moved the trays out of the X-ray machine as well as other metallic objects. Edit: I considered that, but I don't see why it discharges on my laptop specifically, which is not (electrically) grounded. Edit 2: The fact that aluminum makes a capacitor also makes me think the laptop's the source. Edit 3: I also did not do anything that others didn't do, so I don't see how I could've built up charge.
    – Vercas
    Jun 12, 2014 at 16:51
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    This reached the hot network questions? Awesome.
    – Vercas
    Jun 13, 2014 at 9:04
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    FYI, I applied this. I left the laptop on a tray at the end whilst the belt was moving under it, for about 30 seconds (putting my belt back on), and used Naftuli's suggestion to minimize the pain. Next time I picked up the laptop and other items before they reached the end of the belt, and did not get shocked at all. I wish I could accept both answers.
    – Vercas
    Oct 3, 2014 at 18:03

6 Answers 6

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Seems unlikely it's anything more than normal electrostatic discharge. The fact that it only affects you could be related to your clothes or shoes (especially if they are made of synthetic fibers). I also wonder whether the moving conveyor belt could be acting as a Van de Graff generator. Do you not get shocks like that under other circumstances? (I live in a semi-arid region with cold winters and I have a metal laptop and a polyester sofa, so every winter day I get many little shocks...)

Anyway, a good trick is to touch the laptop with a piece of metal, such as a key or coin or paperclip. You hold one end of the key firmly and touch the laptop with the other end, so the spark is away from your finger and doesn't hurt. (You might still feel a little tingle between your fingers and the key.) Unfortunately, since you have to go throug a metal detector, it might not be so easy to have a piece of metal with you, but something like a paperclip might be small enough not to trigger it.

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    I'll be damned. The system may indeed behave like a Van de Graaff generator when the thread is moving but my laptop is not. While I retrieve my belt, coat, etc. the tray containing the laptop is usually behind another tray or even at the end, with the thread sometimes moving under it. This also explains the extremely painful shocks. Since this seems like a good explanation and the proposed solution (increasing the contact surface area) is brilliant, I will accept this answer. Thank you very much for this.
    – Vercas
    Jun 12, 2014 at 17:16
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    A note: a paperclip will set off the metal detector. I've seen it go off on the metal pieces on headbands, for example.
    – Nathan C
    Jun 12, 2014 at 19:10
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    If you place something metal, like your keys, in the bowl to go through the x-ray scanner ahead of the laptop, it will be there to use as a static discharge device later.
    – KutuluMike
    Jun 12, 2014 at 21:10
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    @NathanC I've gone through metal detectors wearing my belt, watch (all metal) and necklace...All at once and separately (some agents are more strict/observant about it) Never set off the metal detector. Somehow doubt that a paperclip would set off the metal detector if all that didn't.
    – Doc
    Jun 13, 2014 at 1:09
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    @Doc: Metal detectors can be somewhat random. I've had my shoelace hooks set off a metal detector gate at Charles de Gaulle, gotten wanded, told to take off my shoes and passed the same detector cleanly, only to later realize that I also had a 10cm+ steel comb in my pocket that it apparently did not react to. Jun 13, 2014 at 22:21
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While certainly not as good as Nate Eldrege's answer, I have a fairly simple solution for dealing with shocks.

Whenever I determine that something is a source of electrostatic discharge, I always put my hand into a fist and discharge with the bottom of my fist (ie: the opposite side that your thumb is on). Tuck your thumb into your closed fist under your fingers. This area certainly isn't as sensitive as your extended finger and will significantly lessen the pain/discomfort of discharge.

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Again tucking your thumb in and making a tight fist, as I have found, lessens the severity of the shock.

Test it out on low-shock items (ie: metal doors, etc.) to get a feel for it.

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    The back of your flat hand is also not very sensitive and has a large surface area to spread the shock. Jun 13, 2014 at 4:04
  • @DavidRicherby It may have hairs, though, as is my case. I need to test this.
    – Vercas
    Jun 13, 2014 at 7:09
  • Touching it first with your nail is also very effective, I've found.
    – Dan
    Jul 2, 2016 at 12:56
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I've had this issue at some security checkpoints and not others.

The difference, in my observation, is in the conveyor belts. I've never had it happen at a checkpoint where the rollers under the belt are metal. If the rollers under the belt are plastic (I think it's Delrin or nylon), it happens very frequently. The charge is being built up by the belt vs. the rollers vs. the plastic bin. Lots of slipping and sliding between all three. (Decades ago I had a toy VdG generator that worked pretty much the same way.)

The best way to discharge it is SLOWLY, through a resistor of about 1 megohm. (By "slowly" here, we're talking about a few milliseconds.)

When you are picking up your stuff, get the resistor out of where you keep it in your laptop bag. Hold one of the resistor's leads in your fingers and touch the other lead to the laptop's metal case. Done.

As others have noted, using a coin or paper clip will also save you from pain. The pain from a discharge of static like this is actually not from the electric current affecting your nerves directly, but from heating at the point where the arc hits your skin. By making the arc hit metal removed from your skin, you avoid this.

HOWEVER.

The reason I suggest the resistor is that even if you don't feel it, sudden static discharge is bad, bad, bad for microelectronics. Laptops are pretty well protected (any assembled product is these days... or should be), but a bit of extra caution can't hurt. By discharging through a 1 meg resistor you bleed the charge off slowly.

(The anti-static wrist straps that people working on electronics wear also use a 1 meg resistor.)

Discharging through a coin, which adds maybe half an ohm of resistance, won't make the discharge appreciably slower.

A 1 megohm resistor of 1/2 or 1/4 watt power rating or so will cost very little, depending on where you buy it and how many you buy at once. You can get a hundred of them on eBay for under 10 bucks. You can get them from any of the electronics distributors on the web (Mouser, Digikey, Newark, Allied, etc.) for 20 cents or less in quantity 1, but the shipping charge may be absurd. If you have a retail store nearby that sells electronics parts that's likely your best bet, even though they'll charge more for the part, you won't pay shipping. Radio Shack catalog number 2711356 will do (but you'll have to buy five of them, for $1.50 for the pack).

The power rating on the resistor won't matter - a 1/4 watt or 1/8 watt rating is fine, as is the typical 5% or 10% tolerance rating. Heck, speaking of tolerance, even the resistance value isn't terribly critical - anything from about 500K to 5 Megohm is good. You want an "axial lead" part, no other type.

Or, if you know an electronics geek, ask them - they likely have several (or many) and will just give you one.

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    I have this same issue. My office floor has carpet, and Saturdays are any dress day, so I just wear simple Slippers. All doors are wooden with metallic handles. Anytime I touch a door after a bit of walking, I get really painful shock. Now what I do is, touch the handle with my knuckle first to discharge, its not painfull at all there, then there is no shock after that.
    – DavChana
    Jul 2, 2016 at 12:21
  • @Davinder As I mention above, reduction of pain doesn't mean you're making the discharge take longer. That's ok for you vs. your office carpet (you won't be harmed by the discharge whether it hurts or not), but to protect electronics you need to slow down the discharge. That's why I recommend the resistor. Jul 3, 2016 at 21:49
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Don't wear woolen socks.

Chances are - your socks are charging on the carpet (as you may be required to take off your shoes) and this causes the static build-up (and then discharge).

Try putting your shoes on first, and touch a metal object (like a desk) before you touch your laptop.

You can also try spraying on anti-static guard on your clothing - do not spray it on your laptop.

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  • Except that discharging to any other metal object results in no static shock. Jul 2, 2016 at 12:26
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Hold the laptop with an item of clothing preferably natural not synthetic and touch the bare machine to any static metal item in the airport. This will discharge the static

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I have another couple of suggestions to reduce the pain of the static discharge:

  • Use the tip of your elbow (an almost totally insensitive patch of skin)
  • Flick the item with your finger (the brain gets the static shock and the impact of the flick muddled up, and for some reason it hurts less. Try it!)

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