EDIT:
I thought the official term for grounding adapter is "ground isolator". That's the reason for this edit - to clarify.

My point is, I was talking about plugging in one of those adapters which turns it into 3-holes from 2-holes.

The image is not showing, just a stock Tripod logo.

99% of the time those ground adapters are useless and can actually be dangerous. If you are truly concerned you should have an electrician evaluate your wiring, or better yet have him run a new circuit to the equipment.

Most of these things called "ground isolator" are hacks to try to get rid of hum from audio circuits. They do nothing to provide safety (and in fact discourage it).

The other isolation transformers will avoid load to ground fault problems, but may introduce other problems.

To see if the receptacle is grounded, you need to pull it out to see if there as a bare or green wire connected to it. Just because someone put a grounding style receptacle doesn't mean they provided the ground.

A 3-prong to 2-prong adapter is NOT a "ground isolator."

They are intended to allow the use of 3-prong equipment on a 2-prong receptacle that is IN A GROUNDED BOX.

NO OTHER USE IS SAFE.

If the box is grounded you can intall a 3-prong receptacle

If the box is NOT grounded, tha adapter will do nothing except let you plug a 3-pring cord into a 2-prong receptacle.

THERE WILL BE NO GROUND.

if there is bx or conduit, a simple test with a multimeter by touching one probe to hot and the other to ground will tell if you have a ground. if the meter reads ''120'', or somewhere around there, you have a ground. a power tester with a neon lamp and 2 probes will do the trick, too.

Wow, what a surprise. Smithy is wrong....again.

NO, a simple test with a tester will ABSOLUTELY NOT verify if a ground is valid or not.

Old AC/BX cable, without the bonding strip, will definitely read as a ground using a meter or tester. This is NOT an indication that the ground is safe to use as an equipment grounding conductor.

where would the bonding strip be?

A test light or meter also won't tell you whether the ground (groundING conductor) has been "bootlegged" or connected to the neutral (groundED conductor).

"where would the bonding strip be?"

Inside the AC cable. If it is not there the sheathing CANNOT be used as an equipment ground.

i didnt say it was legal, i just said it would be a path to the panel. it would be fine if there was a gfi breaker.

"i didnt say it was legal, i just said it would be a path to the panel. it would be fine if there was a gfi breaker."

you didn't say it was not legal either. Please just stop giving people advice, you've been wrong on almost every single one of your posts despite you thinking you're some electrical genius (here's a hint, you're not) ....

Get some actual real experience in the trade rather just installing a few outlets and switches and what you read on the internet.

It would NOT be fine. Please stop spreading dangerous and incorrect information. The entire world's problem can NOT be solved with hospital grade receptacles, QO panels, and GFCI's.

Hi, thanks everyone!

I realized afterward Tripod's quirk with images I post, which are part of a file. They don't seem to allow clickable links for pics, rather just copy/pasted ones.

So the solution is:
to copy/past my URL onto your toolbar:
jpegifs.tripod.com/outlet.jpg

...then it will work. You should then see the pic.

Unfortunately, I'm too much an electronics dummie to understand technical stuff as posted above, rather just wanting to know if my wiring is or/not grounded.

Reason:

I'm sorta electrosensitized by my computer equipment, and been in touch with a filtering expert (he used to produce filters to filter sensitive music). Here's what he emailed me:

"If the source of radiation is the computer screen, filtering the power will probably not be a viable solution, as the radiation is generated within the screen circuitry as a byproduct of producing the image.......I notice in your picture that you appear to have a ground isolator plugged into the wall [he probably meant to say an adapter rather than isolator]. If that is the case, then you are eliminating the ground connection to your power strip. So even if it did have common mode filtering, it would not work because of the lack of a ground connection."

PLEASE NOTE THE PIC I SENT HIM, WAS OF MY SETUP, INCLUDING THE TWO-TO-THREE-PRONG-ADAPTER WITH POWER-STRIP PLUGGED INTO IT.
WHAT I DID NOT SEND HIM, WAS THE PIC POSTED HERE, WHICH I TOOK AFTERWARD.

So, basically, I'm trying to reconcile his words, with my situation, and at least find out if/or/not my outlet is grounded. Because my reasoning tells me that grounded or non-grounded outlets may be only a tiny percentage of the true culprit (i.e. that of the screen circuitry generating radiation). Indeed I find that different screens & laptops have caused me varying symptoms ranging from very bad, to much more tolerable.

no. an adapter will not ground it. just pull a new line from the panel, that is what i would do if it was my house. just use 12awg wire on a 20a breaker, so you can use more power.(i HATE 15a receptacle circuts)

That pic. tells us nothing.

Most people who use grounding adapters (sometimes called ground lifters, at least among the audio folks I know) don't bother connecting the tab to the receptacle cover screw. However, that's the only way they can possibly provide a ground - and as has been said here, even that's not guaranteed to be a usable safety ground.

From what I see of your pic, I think it's safe to expect that there's no bootleg ground there. Whether there is any ground at all, I can't tell from that pic.

If you plug in a grounding adapter and solidly connect the adapter's tab to the receptacle cover screw, providing that screw is bare metal, you can then plug in a 3-light receptacle tester from your hardware store. That will tell you whether you have a ground of some sort.

Note that it won't guarantee that the ground (if present) provides adequate personnel protection. But even a non-bonding-strip BX ground might help somewhat with noise suppression, if that's all you're after.

All that said, it's true that the best answer is to have a properly grounded receptacle installed.

Thanks! sorry re: the picture quality, but you cant imagine what I went thru just for that crummy pic. It involved contortionism and exhausted me.

BTW, I have a Graham-Stetzer power-strip (with built-in filter) http://www.lessemf.com/images/a800.gif, which I'd plugged into the three-hole adapter, and all my equipment such as modem/laptop/adapters plugged into the Stetzer-strip. But it failed to help me.

Now, if y'all don't mind follow-up comments (or, shall i rephrase it "rhetorical questions":

The crux of the matter is, that even at my local library, which recently had professionals ground all their outlets with the whole shebang of steel cables, yada yada,

...and, not only there, but also at other libraries' computer-stations in my area... after awhile, I feel the typical radiation symptoms.

Also as mentioned above, different systems (at my house) cause me worse or better tolerance depending on the system's processor, and/or its screen etc.

Similarly, different systems AT THE SAME LIBRARY are either quite intolerable, or else "way more" tolerable than the former. Usually it's the newer systems which I'd find less tolerable.

Which tells me it's not so much the non-groundedness that's causing me the most harm, but rather, as the aforesaid filter expert said, may be mostly from the radiation generated within the screen circuitry, which NO filters would help, other than just to distance my body from the screen & other radiation sources.

Some eSensitives say cordless mice improve their situation, while others experience the exact opposite, so since I never yet tried a cordless, I may yet try same.

Another eSensitive (like myself) mentioned that "many newer towers" are tolerable to him but NOT "many newer laptops"

(I'd told the aforesaid filter-expert that some electrosensitives have been helped by using projectors, and he responded that a projector probably may be the better way to go, albeit they can still produce RF emissions.

Another alternative is PixelQi which (i gather) enables turning off the backlights.

The person probably best in a position to comment analytically regarding all the above, might be someone knowledgeable in both electronics BUT who himself has also experienced my situation to some degree. I've already been in contact with some such people, but because they themselves were so compromised (or cryptic by nature), I still am not quite resolved. My quest has been ongoing for close to a decade already, and involved alot of monetary loss I could ill afford. Long story.

I don't know anything about "electrosensitivity" so I have no idea whether this will be of help.

However, back when CRT monitors were common, you could buy metallized screens to fit over the screen. These supposedly blocked some of the monitor's non-ionizing radiation (NIR). (CRT monitors actually produced far more radiation to the back and sides than they did to the front, however).

Maybe if you could find one of those, it would help, even with an LCD monitor. It would still need to be grounded, but probably grounding it to the metal of the computer case would be sufficient.

As for the system box, first make sure the case is grounded metal, and properly assembled with all the screws tight. IIRC, most computers' FCC ratings require this for compliance.

Then, just get longer cables and locate the box further away from your desk. All forms of radiation decrease as the square of the distance, so doubling the distance reduces the exposure fourfold. Quadrupling it drops the exposure sixteenfold.

Good luck.

Ah...the deadly cathode rays!

"Ah...the deadly cathode rays!"

Most display noise comes form the scan coils for older CRTs and the electronic scanning for newer monitors.

The nice big scan coils to move the beam around on the screen radiate badly.

There is a lot of area being charged and discharged on flat screens to address the pixels on the screen and it radiates very well also (though at lower intensity than the old CRTs).

We used to demonstrate the leakage from CRT scanning (and the electron gun) by picking up the EMI from a display with a radio designed for the purpose and duplicating the CRT display.
The security folks would panic when we could do this from hundreds of yards away.

David, thanks for the tips. I guess you may be talking about those 3M shields they used to sell. I used to use one of those at work in the 1980's but I'd still get dizzy & bad symptoms.

After all's said, I think the most sure bets for now (at least until the inventor of PixelQi comes out with large-screen PixelQi's) is either the teeny PixelQi's, or else using a tower paired with LG's HS201 projector.

I don't suppose there are any up-to-date CPU-towers with two-prong plugs?

Note that my X31 Thinkpad's adapter has 2-prongs, and it's plugged into the power strip that has an array of 3-hole sockets.

SO...
...is it safe (health-wise) to plug a 2-prong adapter into 3-holes?

"don't suppose there are any up-to-date CPU-towers with two-prong plugs? "

Not if you want the system to survive the first heating season and static electricity.

Not having an actual ground available leaves electronic equipment very vulnerable to static discharge.

I see. but at least, is it safe to plug a 2-prong adapter into 3-holes? I.E. from the perspective of becoming irradited not speaking re: fire or equipment damage.

Also, since I've been told that the cable of a mouse can act as an antenna (transmitting radiation from the laptop to my body (indeed, my mouse-arm tingles & burns, and my right-hand's knuckles became prematurely arthritic)...

...so based on that, I'm wondering:

(1) Whether a USB-mouse would act as less of an antenna than a PS/2 mouse

(2) Are all USB mice optical? Or are some mechanical?

(3) Are all wireless mice optical?

"I see. but at least, is it safe to plug a 2-prong adapter into 3-holes? I.E. from the perspective of becoming irradited not speaking re: fire or equipment damage. "

If you use a 3-prong to 2-prong adapter and fail to connect the tab to ground is is NOT as safe.

Without an actual ground the case and chassis of the equipment are simply floating.

A single static discharge can pick up the case high enough to cause damage.

"I see. but at least, is it safe to plug a 2-prong adapter into 3-holes? I.E. from the perspective of becoming irradited not speaking re: fire or equipment damage"

In terms of safety from irradiation- yes.

As a side note- Just do one of the two following to solve your problem.

1)Have a GFI receptacle installed. 3 prongs in no problem. Safety, no problem.

2)Most laptops come with two prong plugs. making this a moot point. Why don't you get one of those, with an external monitor and keyboard- problem solved without any electrical changes.

1) Whether a USB-mouse would act as less of an antenna than a PS/2 mouse

(2) Are all USB mice optical? Or are some mechanical?

(3) Are all wireless mice optical?

There is no significant difference in the way a USB vs PS2 mouse works. Both use a simple low-speed serial interface with the cpu.

I haven't seen a mechanical mouse offered for sale in years. Optical mice (a friend of mine calls them "neutered mice" :) are more reliable, more precise, and maintenance free to boot, so for most users mechanical mice offer no advantages. If you want a mechanical mouse, you might try flea markets and thrift stores.

Thank you so much, guys! First, to follow up re: mice, I guess that means that cordless mice are usually optical. I was told that optical is worse radiation, though I'm not sure whether they meant corded-optical or cordless optical.
So this remains a mystery until I'd try it myself. Speak of flea market, believe it or not, all I have are mechanical-corded mice.

To ontariojer, thanks!

To follow up, ontariojer, is there any such thing as a 2-hole surge-protector powerstrip, as an alternative for plugging in the following (excluding the laserjet's plug):

Right now I have the following plugged into the 2-to-3 adapter that's plugged into the above pictured 2-hole outlet:

Thinkpad adapter's 2-prong plug:
http://www.buylaptopadapter.com/images/65wattacadapterfori-3.jpg

Comtrend modem adapter:
http://www.meetgadget.com/gadget/25083/COMTREND+CT-5072T/specs

Linksys 2102 power adapter:
http://www.aliexpress.com/product-gs/347036044-Generic-ac-power-adapter-5V-2A-5-5-2-1mm-for-LINKSYS-SPA2102-R-Phone-Adapter-wholesalers.html

3-prong HP laserjet 6L:
http://img1.classistatic.com/cps/po/100821/967r3/1641d57_27.jpeg

Alternatively, I know a non-electrician guy (who just installed the wiring for my DSL line) who can probably install a GFI, but would it be safe for him to do it? He seemed to be quite smart, even if not licensed, and he told me he can ground my outlet.
Is there a video showing how to convert a 1950s outlet to GFI? I did find a video which depicted conversion of a 3-hole outlet to GFI, but wanted to get an idea of what's involved in converting a 2-hole outlet to GFI.

I've never seen a surge strip without a ground. If you could find an old 2-pin plug strip, you could make one with an MOV, but why bother? That's effectively what you have anyway when you plug a 3-pin one into your current receptacle. An ungrounded surge strip provides some measure of protection from surges and lightning, but not nearly as much as a properly grounded one.

As for your DSL friend working on your wiring - I recommend saying "no thanks." In most cities, it is not legal for an unlicensed person to work on your wiring, with one exception - YOU are permitted to do so, *if* you own the home, and *if* you obtain a permit from the city's building department.

I was going to recommend that you install a GFI yourself - the only installation differences between "with a ground" and "without a ground" is that without a ground you simply don't connect anything to the ground terminal, and on the GFI face you stick a label that says "no equipment ground."

But then I looked again at the photo you posted. It's tough to be sure, but the junction box your recept is in doesn't look very generous in size. It might be OK, but I'm a bit concerned that you might have a tough time fitting a GFI in there. I'd hate to have you start the job and not be able to finish it.

So, if you really want a GFI, you can do two things: 1) Hire an electrician to install a GFI. 2) Buy a plug-in GFI adapter from the hardware store.

But I'm not so sure a GFI is what you really want. I'm getting a sense that you think having a ground is helpful for reducing radiation exposure. I don't know if that's so; it's not my area of expertise. However, note that while a GFI will provide protection from electrical shock, and that's a very good thing, it won't provide a ground.

In order to get a proper and safe ground, you'll have to have a new receptacle installed, with a homerun directly back to the house's main panel (breaker or fuse box).

My guess is that your friend who can "ground your outlet" is talking about either "bootlegging" a ground, or running a separate ground wire back to the main panel. The first is dangerous. The second is so much work that you might as well go ahead and do it right, installing a new cable run and a new receptacle. Unless you have the time, skills, and inclination to study up on the techniques of home wiring, that's most likely a job for a pro.

FWIW, I bought my first home computer in 1984. I was living in a late-1950s home where the only grounded receptacles were in the kitchen and garage. I didn't want my $2000 system destroyed by lightning or power surges, so I did as I described above - installed a new, properly grounded receptacle for the computer with a home run back to the main panel. That's what I recommend for you.

To David (and ontario & the rest), thanks so much for all the clarifications & sorry for any delays due to my having become infected yesterday by viruses & trojans upon clicking a link on another forum - ongoing saga.

OK, now, (correct me if i'm wrong) but the gist of what I gather is:

GFI plus surger-strip protects the equipment
GFI protects vs. electric shock to humans
GFI does?/not? protect against radiation
.................................(debated above)
Grounded outlet plus surger-strip protects equipment
Grounded outlet protects vs. electric shock to humans
Grounded outlet protects against NON-AMBIENT radiation

....this last is based on what a music-filter expert told me. He said if the source of radiation is computer screen, filtering the power will probably not be a viable solution, as the radiation is generated within the screen circuitry as byproduct of producing the image. Note he also said that common mode filtering would not work without ground connection.

Now I'm just wondering what it should cost to have a licensed guy ground the outlet...

OK, now, (correct me if i'm wrong) but the gist of what I gather is:

GFI plus surger-strip protects the equipment

The surge strip, without a ground, rovides incomplete but better-than-nothing equipment protection. The GFI doesn't provide any significant equipment protection.

GFI protects vs. electric shock to humans

Correct.

GFI does?/not? protect against radiation

I can't see any way that it would provide such protection.

Grounded outlet plus surger-strip protects equipment

Correct.

Grounded outlet protects vs. electric shock to humans

When the appliance connected to it has a 3-pin plug, this is correct. Adding a GFI further improves shock protection.

Grounded outlet protects against NON-AMBIENT radiation

POSSIBLY correct, when the device producing NIR has some kind of a shield around it to block radiation, and that shield is connected to the receptacle's ground.

For example, the CRT shields I mentioned above were to be connected to a ground.

Braided shielding can also be applied to data cables and the like if they are not currently shielded. (See link below for an example.)

Here is a link that might be useful: Tubular shielding braid for cables

QUOTING DAVIDR: The surge strip, without a ground, rovides incomplete but better-than-nothing equipment protection. The GFI doesn't provide any significant equipment protection.

Thanks! this exactly enabled me with facts I need to know.

Because after reading all the above, I now realize that what makes the most sense for me is to leave things as is.

Because the only way I'd want to bother with grounding the outlet, would be if it would provide BOTH my equipment AND me from protection.

And since the surger-strip at least provides "somewhat" equipment protection, why bother with either grounding, or the GFI...

As for the other suggestion, I do appreciate it, but for now, I'd prefer the easier way out via either trying the lowest-power Netbook such as maybe Asus EEE PC, or using a cordless mouse plus HS201 projector, and keeping the projector/system/modem/router/phone far from my chair.

Trust me, any shielding suggestions which you've offered have probably been tried by electrosensitized guys (who themselves were highly knowledgeable re: electronics). I've been in touch with at least one of them, who must ration his online time, despite all measures he's taken. Note that I never did get around to asking him whether he tried either PixelQi or projector.

"And since the surger-strip at least provides "somewhat" equipment protection, why bother with either grounding, or the GFI... "

A typical surge strip has 3 MOVs inside.
One is hot-neutral, another is neutral-ground, and the last is hot-ground.

The purpose is to keep all three lines within the MOV clamp voltage of each other.

Without a ground the only MOV that can operate is the hot-neutral.

Transients can appear on ANY line or ANY COMBINATION of the lines.

Without a ground available the equipment is very vulnerable.

A GFCI device by itself has NO TRANSIENT protection.
NONE.

If you want to reduce radiation and susceptibility install a correctly grounded 3-wire 120 V receptacle.

While the safety ground (groundING) conductor is not that effective as an RF ground, it is still far better then NO ground.

Thanks. I'm aware that of course a grounded outlet is better, so I'll consider it in future. Thing is, right now, there's a zillion things on my priority list first. Such as malicious viruses/trojans on the tiny (more tolerable) laptop i'd been using, and researching replacement systems while my newer (Dell) is zapping my throat & body w/its radiation. Also busy in personal life.

Again, thank you all so much for your various advices!