* Magnetism, Have We Missed Out The Obvious? Laptop-Users Be Aware!

Jan 26, 2008,10:33 AM

Upon reading the thread about Magnetism Effect from Watch-Winder "Navel Gazing - A Question for Watchmakers and Engineers..." by Harry Tan, I suddenly remembered there is a question I've always wanted to share and ask. 

The little experiments and photos were taken in April 2007, and had forgotten all about it.

I'm a notebook-user, and I've sent 2 watches for abnormal daily rate getting faster without placing my watches near mobile, speakers or even bags with the magnetic clips! 

There is only one thing I use daily and many hours with it..... my notebook (or laptop)!

Coincidentally, I was trying to find some answers and was reading Donald de Carle's Practical Watch Repairing...and there was a chapter on magnetism ( I've enclose a page of it for your reference, and also for the respect of copyrights).

Since magnetism is something we cannot see, how are we going to quantify?

Donald's answer was simple....use a compass.  Logical. 

"Like poles repel, opposite poles attracts."


Agreed with John's ( Ei8htohms) and Mycroft's inputs :

" magnetic field strength drops off as the square of the distance from the source, so every centimeter of separation is dramatically safer for the watch in question."

"The effect of magnetism varies inversely to the square of the distance from the source of magnetism. Therefore when you move a watch away to twice the distance, the effect lessens by 4 times."

However, I believe the time the object expose to the magnetic field has direct impact too.

So that's how the little experiments began ............


First thing, how many of us realise that our wrists are directly on top of the notebooks?

Regardless of brands, it is only logical to place the speakers at the front of the notebooks (directly below the hand-resting areas).

I've used 2 brands to demonstrate the effects and I've tested both sides of the notebooks.

Let the pictures do the talking .................

Figure 1 : For the right-side of this brand, the compass-pointer (marked GREEN ) did not deflect much till it was directly above the speaker area.  The compass-pointer deflected about 180 degrees.

Figure 2 : For the left, the magnetic effect was much stronger.  About 3 cm away from the Right-speaker, the green-pointer deflected as much as 280 degrees!

Figure 3:  Tried on another popular brand of notebook, the effect was visible.  When it was on top of the speaker, the green-pointer deflected by about 270 degrees too.


NOW the question:  So how does it affect the watch on my wrist?

Perhaps Figure 4 may shade some light. 

Figure 4 :  I simulated the watch using a compass instead.  Based on one of the brands (notebook), the pictures on top showed my hands away from the notebook (at least by 10cm or 100mm).  The compass-pointer has no response.   As I placed my hands on top of the notebook-resting-pads, observed the compass-green-pointer deflected.

For the left-hand side, the deflection is near to 180 degrees  while for the right-hand side it was about 90 degrees. 

One more observation...what will happen to the watch on either my wrist at these two positions for at least 2 hours at a stretch?I don't know.  

Since I removed my watches when working long hours (continuously) , they have been behaving well  smile

For your thoughts over the weekend, may save you some monies.




A good reference from the book " Practical Watch Repairing" ... abour Magnetism. Enjoy!

added to Editor's Pick

This message has been edited by AnthonyTsai on 2008-01-26 20:13:01 This message has been edited by Kong on 2008-01-27 09:26:57

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I am keeping my watches

 By: Bill : January 26th, 2008-10:42
But throwing out my lap top. LOL. Only kidding. Lucky for me I am right handed so I don't have to worry about cell phone magnetism. Thanks Kong for the great report and the bad news. Bill

thanks Kong. i spend a lot of the day using my laptop and

 By: G99 : January 26th, 2008-12:35
wearing 2 watches i am willing to accept time gain or loss although i havent actually noticed any. but does it do any damage to the watches themselves? Graham

most of the time it's easily fixed

 By: Chromatic Fugue : January 26th, 2008-13:36

I knew that there was a practical aspect...

 By: Tony C. : January 26th, 2008-14:21
to my collecting vintage IWC Ingenieurs! Thanks for the interesting post. Tony C....  

Kong, useful information. Thanks

 By: ling5hk : January 26th, 2008-19:18
Apart from laptop, handphone also has very strong magnetic field. I haven't done any experiment. Don't know how actually it will affect the watch when you hold your handphone with the same hand. Regards Ling

Knows the source of the magnetism & avoid close proximity...

 By: Kong : January 27th, 2008-10:19
The distance between the handphone and the phone is far, so has no effect, except when ....you placed your watch side-by-side with your handphone. The strongest magnetic field is at the earpiece (the speaker)! I believe in taking precaution.... a few of o...  

Very interesting post Kong!

 By: AnthonyTsai : January 26th, 2008-20:16

great stuff, thanks! (nt)

 By: ei8htohms : January 26th, 2008-21:32

Thanks, Kong,

 By: masterspiece : January 26th, 2008-22:11

Great post Kong

 By: waien : January 26th, 2008-23:01

Doubt so...a soft iron cage also has 'weak points' like....

 By: Kong : January 27th, 2008-10:29
the date-window, the hole/s of the hands (hr, min, sec) and the crown. It depends on the strength of the magnetic source So prevention is better. Kong

Not so sure about that.

 By: tony p : January 27th, 2008-23:10

Hmmm . . . some of my favorite watches are . . .

 By: Dr No : January 27th, 2008-08:48
. . . the Ingenieur, Milgauss, and Railmaster, both vintage and modern . . . I thought it was primarily for aesthetic reasons, but perhaps there was a magnetic subtext as well . . . curiously, Art

Thanks, Kong, great detective work!

 By: ThomasM : January 27th, 2008-20:43
I'm particularly sensitive to magnetic fields, and get a headache just from using cell phones - a bona fide, wave pressure migraine just from having an active cell phone operating near my head/ears. But it is a good idea to note that EMI and RFI are relat... 

Good information, Kong. From now on, i will only be...

 By: Ronald Held : January 28th, 2008-05:45
wearing quartz watches when doing a lot of work on my laptops.

Not sure about quartz.

 By: yw wong : February 4th, 2008-23:02

interestinf findings

 By: damien : February 29th, 2008-09:35