In order to protect people at their workplace or in their home from low-frequency magnetic fields, entire rooms can be shielded. A reference project is described below.

Panorama Park Emmenbrücke Lucerne

A double-track railway line runs directly along the Panoramapark commercial property. The distance between the workplaces and the overhead lines is only a few metres. Measurements in the rooms of the property have revealed magnetic field peak values of up to 9 µT (microtesla) and 24-hour average values of around 2 µT. Since the installation limit value, AGW (1 µT averaged over 24 hours) according to the ordinance on Non-Ionising Radiation, NISV, was clearly exceeded, shielding measures had to be taken to limit the fields.

A simulation was used to visualise the expected effect of the planned shielding measures. In such simulations, the currents of the contact conductors, transmission lines and the return currents in earth conductor cables, rails and soil are taken into account. With such a simulation, the shielding concept can be checked.

The Systron PowerShield® passive shielding system was chosen for field reduction. This effectively protects small rooms, open-plan offices or entire floors from magnetic fields. In order for railway fields to be effectively reduced, the shielding plates must usually be mounted on all sides, i.e. on walls and on the floor and ceiling. In the project, two open-plan offices were shielded on all sides. Shielded in this way, the fields can no longer penetrate into the rooms, and people are protected accordingly.

 

As part of the renovation of one of the floors of the property, Systron PowerShield® room shielding was installed in two of the open-plan offices. The rooms were shielded on all sides, i.e. on floors, walls and ceilings. Only the windows were left out.

To prove the effect of the measures, measurements were taken before and after installation of the room shields and compared with each other. Both the peak value and the average value were significantly reduced with the measures and the limit values were complied with.

In this project, the magnetic fields could be significantly reduced with the Systron PowerShield® room shielding system and thus the limit values were clearly complied with.