Whilst the number of incidents involving the quench of a magnet is rare, the ability to be able to monitor any leakage of cryogen into the scan room can help to ensure the safety of all involved. The OxiQuant MC® has been designed to give a warning of depleted oxygen levels in the scan room. The unit is simple to fit either during the installation of the scanner or afterwards and does not require the scanner to be ramped down. It can be linked into an extraction system to allow automatic switch on if oxygen levels drop. Continuous sampling of the oxygen content from single or multiple locations within the room are achieved by drawing a steady flow of air across the oxygen fuel cell detector at a predetermined velocity.