Comments on: How does a Magnetic Shield work? http://mumetal.co.uk/2009/03/11/how-does-a-magnetic-shield-work/ Magnetic shielding with mu metal Wed, 30 Mar 2011 15:22:51 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: nickmsl http://mumetal.co.uk/2009/03/11/how-does-a-magnetic-shield-work/comment-page-1/#comment-319 nickmsl Thu, 23 Sep 2010 08:52:24 +0000 http://mumetal.wordpress.com/?p=9#comment-319 Dear Sir, Firstly, you are correct in assuming that mu metal is the ideal type of shielding at 60 Hz and low fields. You could use foil to wrap around sides and back of the pick up as you suggest. The main problem with this is that mumetal is very magnetostrictive, and this means that it will lose significant amounts of its shielding properties when bent, so normally it would be best to fabricate a shield and then carry out the special high temperature heat treatment to develop the material properties fully. Obviously, from an aesthetics point of view, a fabricated shield would also be far more visually pleasing than a bent foil shield. With Kind Regards Dear Sir,

Firstly, you are correct in assuming that mu metal is the ideal type of shielding at 60 Hz and low fields.

You could use foil to wrap around sides and back of the pick up as you suggest. The main problem with this is that mumetal is very magnetostrictive, and this means that it will lose significant amounts of its shielding properties when bent, so normally it would be best to fabricate a shield and then carry out the special high temperature heat treatment to develop the material properties fully. Obviously, from an aesthetics point of view, a fabricated shield would also be far more visually pleasing than a bent foil shield.

With Kind Regards

]]> By: Bent Romnes http://mumetal.co.uk/2009/03/11/how-does-a-magnetic-shield-work/comment-page-1/#comment-303 Bent Romnes Fri, 17 Sep 2010 19:26:15 +0000 http://mumetal.wordpress.com/?p=9#comment-303 I wind pickups for guitars and pedal steel guitars. I am having trouble with interference form the 60 cycle hum. Would you recommend your mumetal ? If so, I would appreciate it if you tell me how I use it i.e. build a "cage" around the pickup for example. The pickups are made out of 10 1/4"x 3/4" pole magnets and 1000's of copper windings around the magnets in order to achieve a resistance of up to 19000 OHM Thanks,and looking forward to your reply. Bent I wind pickups for guitars and pedal steel guitars. I am having trouble with interference form the 60 cycle hum.
Would you recommend your mumetal ? If so, I would appreciate it if you tell me how I use it i.e. build a “cage” around the pickup for example.
The pickups are made out of 10 1/4″x 3/4″ pole magnets and 1000′s of copper windings around the magnets in order to achieve a resistance of up to 19000 OHM
Thanks,and looking forward to your reply.
Bent

]]> By: nickmsl http://mumetal.co.uk/2009/03/11/how-does-a-magnetic-shield-work/comment-page-1/#comment-291 nickmsl Thu, 16 Sep 2010 07:38:52 +0000 http://mumetal.wordpress.com/?p=9#comment-291 Dear Sir, Thank you for your question. In order to help with your query I would need some further information; 1. What is the magnetic field strength that you are trying to shield out? 2. What is the proximity of the field strength to the sensor? 3. Do you have a reading from a Hall probe at the sensor? (not essential) 4. What thickness mumetal are you currently using? Also a brief sketch of the current set up would be advantageous to obtain a further understanding of your current shield shape and position. With Kind Regards, Dear Sir,

Thank you for your question.

In order to help with your query I would need some further information;

1. What is the magnetic field strength that you are trying to shield out?
2. What is the proximity of the field strength to the sensor?
3. Do you have a reading from a Hall probe at the sensor? (not essential)
4. What thickness mumetal are you currently using?

Also a brief sketch of the current set up would be advantageous to obtain a further understanding of your current shield shape and position.

With Kind Regards,

]]> By: yannick http://mumetal.co.uk/2009/03/11/how-does-a-magnetic-shield-work/comment-page-1/#comment-287 yannick Mon, 13 Sep 2010 13:16:47 +0000 http://mumetal.wordpress.com/?p=9#comment-287 Hello I am currently working on a mumetal based protection for a sensor I want to protect the sensor from an horizontal magnetic field so I designed some kind of bell which I put on my sensor. However I still get teh perturbations. Can you explain me how the field lines will react to such a protection ? Thank you in advance Hello
I am currently working on a mumetal based protection for a sensor
I want to protect the sensor from an horizontal magnetic field so I designed some kind of bell which I put on my sensor.
However I still get teh perturbations. Can you explain me how the field lines will react to such a protection ?

Thank you in advance

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