Shielding low-frequency magnetic fields

MuFerro™ Low-Frequency Magnetic Shielding

Magnetic Field Reduction for Technical, Medical and Industrial Environments

MuFerro™ shielding is designed to reduce low-frequency magnetic fields around transformers, busbars, high-current installations, laboratories, medical equipment and other sensitive environments.

Holland Shielding Systems supports the complete process from magnetic field measurement and engineering to in-house production, installation and verification.

DC to 100 kHz

Suitable for low-frequency magnetic shielding from DC to 100 kHz.

Optimized for 50/60 Hz

Designed for applications around transformers, busbars and power installations.

Material or Complete Project

Available as sheet material or as part of a project-specific shielding construction.

Applications

Where MuFerro™ Magnetic Shielding Is Used

Low-frequency magnetic fields can occur around transformers, busbars, high-current cables and other electrical installations. MuFerro™ shielding can help reduce these fields where sensitive equipment, measurement systems or occupied areas are located nearby.

MuFerro low-frequency magnetic shielding for transformer rooms and substations
Transformer Rooms and Substations

Magnetic field reduction around transformers, substations and electrical rooms.

MuFerro low-frequency magnetic shielding for busbars and high-current cables
Busbars and High-Current Cables

Field reduction around busbars, high-current cables and power distribution systems.

MuFerro low-frequency magnetic shielding for medical facilities and diagnostic equipment
Medical Facilities and Equipment

Magnetic shielding for medical rooms and sensitive diagnostic equipment.

MuFerro low-frequency magnetic shielding for laboratories and sensitive measurement equipment
Laboratories and Sensitive Measurements

Shielding for laboratories, measurement rooms and technical research environments.

Why Use Low-Frequency Magnetic Shielding?

Low-frequency magnetic fields can interfere with monitors, measuring equipment, medical systems and other sensitive electronics. They can also extend into offices, laboratories or other areas near electrical installations.

The required reduction depends on the source, frequency, field strength, distance, geometry and project requirements.

What Holland Shielding Systems Provides

  • Magnetic field measurement
  • Field source identification
  • Shielding advice and engineering
  • In-house production
  • Installation support
  • Verification measurement
Measured Project Example

Office Above a Transformer Room

A customer wanted to convert a storage room directly above several power transformers into an office. Elevated magnetic fields caused interference with computer displays in the room.

Step 1
Problem

An on-site measurement showed a magnetic field strength of approximately 750 nT inside the intended office.

Step 2
Shielding Solution

A custom MuFerro™ umbrella shielding construction was engineered above the transformers without relocating the existing installation.

Step 3
Measured Result

Before: 750 nT

After: 80 nT

Measured reduction: approximately 89%.

Magnetic field measurement before installing MuFerro low-frequency magnetic shielding
Before Shielding: 750 nT
Magnetic field measurement after installing MuFerro low-frequency magnetic shielding
After Shielding: 80 nT

Heavy Transformer Shielding Example

Project-specific MuFerro™ constructions have also been developed for demanding transformer applications in military and medical environments.

  • Heavy-duty shielding construction
  • Designed around existing electrical equipment
  • Adapted to available installation space
  • Custom engineering and in-house production
Heavy MuFerro low-frequency magnetic shielding construction around transformers
Material and Technical Data

MuFerro™ Magnetic Shielding Material

MuFerro™ is suitable for low-frequency magnetic shielding from DC to 100 kHz and is optimized for 50/60 Hz applications. Material selection and layer build-up depend on the magnetic field source, magnetic flux density, required reduction and construction.

Material Applications

  • Standard sheet size: 2000 x 1000 mm
  • Can be applied in multiple layers
  • Suitable for walls, floors and ceilings
  • Suitable for local shielding around magnetic field sources
  • Suitable for new installations and retrofit projects
  • Can be incorporated into custom shielding constructions
MuFerro low-frequency magnetic shielding material from Holland Shielding Systems

MuFerro™ Types and Technical Specifications
Property Unit MF-FS MF-ECFC
Density g/cm3 8 4
Thickness mm 0.7 4.7
Resistivity Ohm·m 5E-7 3E-7
Curie temperature °C 400 400
Maximum μr at DC - 3800 3800
Maximum μr at 50 Hz - 3750 3750
Maximum μr at 60 Hz - 3700 3700
Minimum yield strength N/mm2 300 105
Minimum tensile strength N/mm2 400 85
Hardness N/mm2 150 30
MuFerro™ MF-FS

MF-FS combines magnetic permeability with suitable saturation characteristics and can be applied in multiple layers for low-frequency magnetic field reduction.

MuFerro™ MF-ECFC

MF-ECFC combines magnetic properties with additional eddy-current performance and can be spot-welded on-site to create a more continuous shielding surface.

MuFerro™ Magnetic Performance Data
DC Performance

The graph shows the relative permeability of MuFerro™ under DC magnetic field conditions.

MuFerro DC relative permeability performance graph for low-frequency magnetic shielding

Please note: These values are measured under laboratory conditions. Results may vary in other situations; please read our Guarantee

AC Performance at 50/60 Hz

The graph compares the relative permeability of MuFerro™ at 50 Hz and 60 Hz.

MuFerro AC relative permeability performance graph at 50 Hz and 60 Hz

Please note: These values are measured under laboratory conditions. Results may vary in other situations; please read our Guarantee

Magnetic Shielding Characteristics

Magnetic shielding performance can be expressed as a shielding factor. The achieved reduction depends on magnetic field strength, frequency, material type, number of layers, geometry and installation quality.

Magnetic shielding reduces magnetic field strength. It does not completely block the magnetic field.

MuFerro shielding factor for low-frequency magnetic field reduction
Installation

MuFerro™ Installation Options

MuFerro™ shielding can be integrated into new construction or installed around existing electrical equipment. The final configuration depends on magnetic field distribution, required reduction and available installation space.

MuFerro retrofit magnetic shielding installed above a transformer room
Existing Installations

Retrofit Installation

MuFerro™ shielding can often be installed after transformers, busbars or other electrical equipment have already been installed.

Depending on field distribution, shielding can be installed on walls, ceilings, floors or directly around the source.

Finished room after installation of magnetic shielding
Final Integration

Finishing After Installation

The shielding can remain visible in a technical room or be covered as part of the final wall, floor or ceiling construction.

The final finish depends on the project requirements and intended use of the room.

Measurement and Verification

Verify the Achieved Magnetic Field Reduction

The magnetic field can be measured before engineering and again after installation to evaluate the achieved reduction.

Measurement positions and operating conditions should be documented so the results can be compared under similar conditions. A measurement report can be supplied when required.

MuFerro magnetic field measurement and shielding verification

Typical MuFerro™ Project Process

1. Measure

Identify the magnetic field source, field strength, frequency and affected area.

2. Engineer

Determine the shielding area, material type, geometry and required layer build-up.

3. Produce and Install

Produce the shielding components in-house and prepare the project-specific installation.

4. Verify

Use a follow-up measurement to evaluate the achieved magnetic field reduction.

Information Required for a MuFerro™ Quotation

To assess your magnetic shielding project, please provide as much of the following information as possible. If some details are unavailable, our specialists can help determine what is required.

1. Drawings and Dimensions
  • Cross-sectional sketch or drawing
  • Dimensions of the field source
  • Dimensions of the protected area
  • Available installation space
2. Position and Distance
  • Horizontal distance from the source
  • Vertical distance from the source
  • Position above, below or next to the source
  • Location of sensitive equipment or occupied areas
3. Technical Data
  • Current in amperes
  • Transformer capacity in kVA
  • Transformer, cable or busbar type
  • Operating frequency
  • Available magnetic field measurements

Not all information available? Send us what you have. Our engineers can help determine which additional measurements or technical details may be required.

MuFerro™ Project Support

Need Help with a Low-Frequency Magnetic Field Problem?

Send us your drawings, technical data, measurement results or a short description of the problem. Our engineers can assess whether MuFerro™ shielding is suitable for your application.

We can support your project from measurement and engineering to production, installation and verification.

Discuss your magnetic shielding project →

Useful Information to Send

  • Drawing or project layout
  • Magnetic field measurements
  • Source and electrical data
  • Required field reduction
  • Available installation space
More results