Available from Alvi Technologies , oxygen alarm systems can be used in MRI rooms to help to detect when oxygen levels fall below the safe amount.

Magnetic resonance imaging (MRI) is a medical imaging technique commonly used in radiology to visualise detailed internal structure and limited function of the body.

MRI provides much greater contrast between the different soft tissues of the body useful in neurological (brain), musculoskeletal, cardiovascular, and oncological (cancer) imaging.

An MRI scanner uses a strong magnet and radio-frequency waves to generate an image. MRI magnets generate 30,000 to 60,000 times greater than the earth’s magnetic field and the magnetic field of MRI scanners is generated by passing electricity through the magnetic coils of wire.

These coils are cooled by helium (Cryogenic gas) and in MRI rooms there is always the danger of cold helium gas spreading throughout the patient area.

Helium Gas is lighter than air and can fill a room downwards by creating an oxygen deficient atmosphere. Helium is odourless, non-toxic, non-flammable gas but can cause the risk of asphyxiation. It is always recommended to install oxygen monitoring systems or oxygen alarm systems that can warn in case the oxygen falls below the safe level.

The oxygen in air is normally 21% Vol and at below 19% Vol O2 the ability of humans to respond may get limited.

The recent technological advancement in gas monitoring systems has seen number of alarm systems for oxygen depletion monitoring.

During sizing and selection of oxygen alarm systems, the following feature should be considered:

  • The MGC gas controller to have display and key pad for settings 
  • MGC gas controller should have Lo-Alarm LED and Hi-Alarm LED 
  • MGC Gas Controller should also have built in alarm buzzer 
  • MGC Gas Controller should have 2 x adjustable relays to trigger external warning system (siren, flasher) or ventilation fans to normalise the oxygen concentration at 21% Vol 
  • Modular Gas Controller MGC-03 to have the capability to be interfaced with 1 – 2 remote oxygen depletion sensor/transmitter 
  • GEL Type electrolyte sensing cell where no more one has to replace the electrolyte every 3 – 6 months. These types of Oxygen cells have gold contacts with expected life of 1-2 years 
  • The Oxygen Sensor/Transmitter should have multi output 0-10V, 2-10V, 0-20mA, 4-20 mA so that can be interfaced to industry standard PLC, SCADA, BMS or gas controller to generate audio-visual alarm as warning 
  • The system should come with auto-diagnostic watchdog which should generate error codes signifying the type of fault with fault LED 
  • Plug- in sensor cell for easy service and replacement: Once the cell life expires it can be replaced by the user themselves by plugging in a new O2 cell 
  • Plug-in PCB for easy service and replacement 
  • In addition it should have 1 x analogue output for PLC, BMS 
  • The oxygen Sensor/Transmitter needs to be installed on the ceiling heights as helium is lighter than air (should be accessible for service) inside the risk room 
  • The Gas Controller MGC-03 should be installed outside the risk room, near the entry door , so that one can monitor the situation from outside without entering the risk room 
  • The Warning Alarm of the oxygen deficiency detectors needs to be installed outside to prevent people from entering in case of oxygen depletion. The alarm should also be inside the risk room so that people from inside can come out safely in case of alarm
It is always recommended to connect the oxygen alarm system to a ventilation fan so that the oxygen deficient atmosphere can be dissipated.