Electromagnetic field shielding with MU-metal – Part 3

What to do in the case of radiation problems found with transformer, high-voltage power cables or electrical train or tram lines?
First, we have to break down the problem into two sections: Electric fields and magnetic fields.

Effective shielding against electric fields with GPA mesh or T98

Electric fields are easy to deal with. Here one can use the GEOVITAL GPA shielding mesh or GEOVITAL shielding paint T98. Hereby, an electrically conductive barrier is applied between the source and the living / sleeping areas, which is subsequently grounded. Better yet, as can been seen in the image above (Dipl. Ing. Johannes Kautz during measurements after T98 shielding application) is to shield the entire house, apartment or bedroom / kids room into effectively a Faraday cage.

It is not so easy with magnetic fields. The only effective remedy to shield against Magnetic Fields is by using a product called MU-metal. However, as Mu-metal is extremely expensive, one tends to say that in practical terms, it is not possible to shield against magnetic fields, as no family could afford it.

The history of MU-metal

What started the development of MU-metal? Mu-metal was developed by British scientists Willoughby Smith and Henry Garnett and it was patented in 1923. It was used in underwater telegraph cables. In the seventies it played an important role when NASA began with the Space Shuttle program. They wanted to move away from the ‘Saturn’ rocket and move towards a spacecraft which was reusable. After the last Apollo flight in 1972, the Shuttle became the workhorse of NASA in 1981.

However, the development of the Space Shuttle brought unexpected problems. The flight computers had to fulfil enormous tasks, required enormous currents and thus produced enormous magnetic fields.

One must consider that this was still a time when computers were something very special. Home computers didn’t even exist yet. The first (Apple II) only hit the market in 1977, Microsoft presented its MS-DOS operating system in 1981 and Windows first appeared in 1985.  Essentially, the computers in the seventies were really only big calculators. Presumably, a smart phone from today provides more computing power than the total computing power of the Space Shuttles from back then.

Space Shuttle test flight

Space Shuttle test flight

These enormous amounts of energy and magnetic fields of the flight computer caused big problems. There were many computer crashes. To prevent a ‘crash’ during flight tests, a Boing 747 was put under the spacecraft.  The problem was, they could not get the spacecraft to fly.  The Space Shuttle program was almost doomed to fail, when NASA scientists found the solution by using this alloy called MU-metal.

Only now it was possible to partition the computers from each other and isolate them, so that they no longer bothered each other.

The problem with MU-metal has been that it has never found its way into mass industry.

Mu-Metal as shielding against EMR is too costly for families

Mu-Metal as shielding against EMR is too costly for families

Few specialist companies now offer solutions based on MU-metal. Most are in semiconductors and wireless communication industries where MU-metal is installed in very small quantities. To shield a house or just a transformer, large surfaces need to be shielded and thus large amounts of MU-metal, and it has a price tag similar to gold and platinum.

Some dealers on the internet, market materials that shield against magnetic fields or material that contain MU-metal. Caution is advised in these circumstances because whilst some shielding against magnetic fields may be present, for the most part it is much too weak to be effective. In these instances, expenses and costs are disproportional to the results achieved.

There have also been dealers offering materials as being MU-metal, where in fact it wasn’t MU-metal at all.


Shielding from low frequency electric fields is possible using GEOVITAL’s products – low frequency magnetic fields cannot be shielded against!

After the problems were solved by NASA, it was the USS Enterprise that was the first airworthy shuttle that flew free of the Boing for the first time on 12th August 1977.


About the Author:

As Geobiologist and Building Biologist (IBN) Dip. Ing. (FH) Klaus Schwärzler has played an important role in the planning of many new buildings in his 18 year experience. He is not only familiar with the illness related side of patients, but knows the technical details and counter measures to create healthier living spaces and lives. His motto: “Only when one has experienced issues and implemented the improvements, do you know what you are talking about…”


  1. George Blake 13/05/2024 at 3:43 am - Reply

    I don’t know where you are getting your information from regartding muMetal. MuMetal was heavily used in the electronics industry. It was used by TekTronix ads a shiled for Cathode Ray Tubes (CRT) in their oscilloscopes. MuMetal was used extensively for chassis, frames, shileds, etc. YOUR version of MuMetal may be over-p[riced and no one wants to buy it, but there are plenty of othr vendors out there that sell it.

    • Patrick van der Burght 14/05/2024 at 1:23 am - Reply

      It may be pricing has come down since this older article George, but the problem we keep facing is that in residential settings the use of MU-metal often produces disappointing results as the source of magnetic fields cannot be well inclosed by it, or the space needing to be protected cannot be fully shielded with it. Especially when it is the resident’s own wiring, the reason for the magnetic fields should be addressed (net current) rather than leaving the problem in place and trying to shield it in the hope that it works.

  2. Patrick van der Burght 11/05/2015 at 9:31 pm - Reply

    Hi Marc, thank you for the article.
    It might be interesting to mention, that according to a local MU-metal distributor here, the application of MU-metal may show disappointing results if it is not applied like a ‘box’, to all walls and ceilings, and even the floor. What this means in more practical terms for a home owner, is that the costly application of just one wall with MU-metal against an obvious problem like a meter box or bank of meters, may bring disappointing results anyway.

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