Kong
[Moderator]
7855
Magnetism, Have We Missed Out The Obvious? Laptop-Users Be Aware!
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 ............
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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 
For your thoughts over the weekend, may save you some monies.
Kong
A good reference from the book " Practical Watch Repairing" ... abour Magnetism. Enjoy!
For link to Kong's original post in HOME forum, CLICK HERE
