MEG, transformers and room shielding
To guarantee the accuracy of the most sensitive instruments — electron microscopes, MEG systems or advanced research equipment — a perfectly controlled magnetic environment is essential.
MECA MAGNETIC has been responding to requests from local authorities, public organisations and private companies for
almost 10 years : Magnetic shielding of zero Gauss rooms or shielded cabins, transformers and low-field rooms…
There are several types of shielded rooms that require different solutions:
– MEG rooms : for medical imaging
– Zero Gauss rooms: for research and experimentation (optronics, electronic microscopes, squid …)
– Transformers and low-field rooms: to stabilize ambient magnetic variations and reduce pollution levels.
MEG rooms
Magnetoencephalography (MEG) uses extremely sensitive sensors, such as SQUIDs or OPMs, to measure the tiny magnetic fields produced by neural activity. As these signals are a billion times weaker than the Earth’s magnetic field, a perfectly controlled magnetic environment is essential to ensure the quality of the measurements. MEG rooms therefore require effective magnetic and RF shielding to eliminate ambient interference. This technology makes it possible to record the magnetic fields generated by neural activity in the brain with very high temporal precision (on the order of milliseconds).
MMC Shield is our multi-layer magnetic shielded cabin.
It is based on a robust, self-supporting structure made of non-magnetic material and covered with an antimicrobial and aesthetic coating. Its function is to successively attenuate the static and dynamic magnetic field in a frequency spectrum ranging from DC to 1000 Hz. This assembly, designed to take into account ambient interference in urban environments, offers a very high attenuation factor that enables it to meet the requirements of OPMs, sensors used for MEG, and also provides an environment with very low residual magnetic fields. The MMC Shield can be equipped with an optional demagnetisation system to eliminate residual magnetism.
Technical characteristics and performance:
- Internal volume: 2 m x 1.5 m x 2.2 m (LxWxH) – custom designs available
Total mass: 2.2 t
Residual magnetic field (static): < 5 nT
Attenuation factor:
DC: > 10,000
Near-DC: > 2,000
AC: > 5,000
Attenuation coefficients on the three axes (X, Y, Z) exceed the technical specifications for the required frequency ranges.
Zero Gauss rooms
These rooms are mainly ordered by public or private laboratories in order to eradicate magnetic fields from a work area. The following applications are concerned: electron microscopes, optronics rooms, tomography rooms… After the installation of a magnetic shielding, the residual field can reach a few nano Tesla. This passive shielding can be completed with an active shielding (subcontracted), in order to further improve the required performances.
MECA MAGNETIC has an experienced and qualified design office capable of designing the shielding magnetically and mechanically, carrying out the necessary measurements on site (France or neighbouring countries), ensuring the supply of materials, heat treatment, permeability tests, installation and final inspection (which can also be subcontracted on request). The integration of active shielding (outsourced to recognized subcontractors in the sector) is also possible.
The rooms are made of permimphy , often in multi-layers, and depending on the frequencies disturbing the environment and the field attenuation required, they can be completed with layers of iron-silicon, pure iron or aluminum.
Transformer shields and low field rooms
Transformers produce electromagnetic radiation, which causes environmental pollution and thus interferes with the operation of nearby workstations (electronic devices). Transformer shielding can also be part of a risk prevention policy.
A computer server room can generate the same type of problems; we then speak of low field rooms.
MECA MAGNETIC provides you with its teams who will design the shielding magnetically and mechanically, carry out the necessary measurements on site (in France and continental Europe), supply the materials necessary for the elaboration of the shielding, ensure the installation and the final control.
The required shielding surface will be optimized taking into account the configuration of the considered building and the need for magnetic attenuation. We mainly work with multilayer materials, with compositions such as pretreated aluminum-metal or silicon-aluminum iron.
Significant applications
Optronic room shielding
Design, production and installation of a shielded room for conducting optronics experiments in a residual field environment of less than 0.5 microtesla.
Transformer shielding
To be completed in 2022 in a secondary school.
MEG Shielded Cabin
Completion in 2024 at a University Hospital Centre: Shielded MEG (Magnetoencephalography) cabin combining passive shielding (cabin) and active electromagnetic field corrector, specifically designed to house MEG brain activity measurement …
They trust us
A tailor-made support
MECA MAGNETIC has a design office capable of assisting you, with a perfect mastery of heat treatment, in the design of your shielding needs, a capacity to supply quality material (with control), a network of subcontractors recognized in their markets and the possibility of installation (France or neighbouring countries).
Here again, we know how to adapt to a wide variety of needs expressed in our field of expertise, whether in room sizing, attenuation needs or customer typology:
- – Assistance/adjustments in magnetic and mechanical design
– Study of complementary solutions to passive shielding
– Material supply
– Thermal treatment
– Delivery
– On-site installation (on request)
– Final inspection
FAQ
Do you travel to perform upstream measurement and final inspection?
Yes, when we deem it necessary or upon specific request. When shielding a room or shielded cabins, we carry out these measurements or mandate an independent, certified organization to validate the proper execution of the contract.
Do you carry out installations on site?
Yes, this is possible in France or neighbouring countries.
Passive shielding, active shielding : what is the difference?
An instrument emits a magnetic field. When shielding, the magnetic field can be absorbed by a metal shield; this is passive shielding. The magnetic field can also be neutralized by another instrument which emits an opposite magnetic field of equivalent value, thus eliminating the residual field in a limited space: this is active shielding. The skill in shielding is to balance the two solutions, which complement each other when the residual field requirement is very low.
How do you ensure the quality of your material?
Each time we receive material and before it is put into stock, we follow defined instructions and procedures:
– the material certificate, which includes a laboratory evaluation of the material performance
– the total weight of the delivery
– the dimensions of the plates
– the thickness of the plates
– for room projects we also perform a material permeability test on samples taken after heat treatment
Are there any standards for magnetic fields?
The directive that applies on electromagnetic fields is the European directive of June 2013 (2013/35/EU – https://eur-lex.europa.eu/).
Each European country may have national regulations that are stricter than this European regulation. This is for example the case in France with the Decree No. 2013-1162 – legifrance.gouv.fr Decree No. 2013-1162 of December 14, 2013 which defines a stricter framework for certain sensitive environments (hospitals, schools …).
A Zero-Gauss part is a part composed of one or more layers of materials with high magnetic permeability (Mumetal in particular) in order to achieve extremely low residual magnetic fields.
The ambient magnetic field can strongly interfere with the calculation results of an electron microscope in optronic rooms. The aim of a shielding system is therefore to reduce the magnetic field as much as possible. In the implementation below, MECA MAGNETIC has designed, produced and installed a shielded room intended to carry out optronic experiments ensuring a residual field environment of less than 0.5 micro tesla, in a highly polluted electromagnetic environment.
Transformers generate magnetic fields in their immediate environment which can lead to computer or electronic malfunctions and possible occupational health problems. Therefore, a transformer room can be shielded.