Magnetic field measurements | Magnetically Shielded Room (MSR)

Low-noise magnetic field measurements in a magnetically shielded room (MSR)

Fraunhofer IPM disposes of a state-of-the-art magnetically shielded room (MSR), which has been specially designed for low-noise magnetic field measurements. An excellent shielding effect for all frequencies is achieved by highly permeable materials: two shells of Mu metal for low-frequency shielding and an aluminium shell for high-frequency shielding. Due to the remanence of the Mu metal, it is necessary to demagnetise the MSR regularly to keep the static magnetic fields inside at a few nanotesla. At the core of the MSR (inner 1 m³), we achieve reproducible residual magnetic fields of about 1–2 nanotesla. In addition, the shielding effectiveness of the MSR increases significantly along with the frequency of the noise source. Hence, it is possible to subdue ambient noise sources by orders of magnitude in order to perform accurate measurements.