To avoid interference from external magnetic fields, MRI systems are installed in magnetically shielded rooms. Although generally very efficient, variable background fields can be problematic, and the cause can be very obscure, such as the return current of a train passing many kilometers away. Such situations often call for “active“ shielding systems that monitor the environmental fields and compensate for them in real-time with a set of coils built into the walls.

Metrolab’s NMR teslameter systems are the perfect tools to track down such problems. They allow ultra-precise, long term monitoring of the magnetic field exactly where it counts – in the imaging area. They can also be used to verify – and certify! – the performance of active shielding systems.