Bruker BioSpec 117 AVANCE III, Manual

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ID: 182463115 11
Safety
2.2.1.1 Control area
The control area is the three-dimensional area in which the magnetic field strength is 0.5 mT
and higher. It is defined by the 0.5 mT stray field line of the particular magnet types.
The MR system owner must ensure that the area can only be accessed by authorized person-
nel. All access to the control area must be clearly marked for the user, e.g. by a combination of
warning signs
,
labels
, and
physical barriers
.
2.2.1.2 Exposed area
The exposed area is the three-dimensional area in which the magnetic field strength is between
0.1 and 0.5 mT. It is defined by the corresponding stray field lines of the particular magnet types.
The exposed area is not a general area of risk.
Within the exposed area, sensitive equipment may experience impairment of functionality, dis-
turbance, or defects.
2.2.1.3 Exhaust system
To rule out the risk of asphyxiation or injury during a quench of the magnet, the magnet can only
be delivered and installed if an exhaust vent system is available and operational.
When planning the exhaust vent, attention should be paid to:
▪ the exhaust vent and the discharge areas are permanently fully functional
▪ the gas leaving in the discharge area does not constitute a risk for people, animals, or ob-
jects.
▪ that a safe ventilation systems is also required even if the magnet is cold but not energized.
2.2.2 Safe handling of cryogen liquids
Cryogenic liquids (liquid helium and to sometimes nitrogen) are used in the magnets to maintain
superconductivity. The handling and storage of these extremely cold liquids requires compliance
with the safety measures described in the chapter
Warning notices [

9]
and may only be car-
ried out by authorized personnel.
If storage facilities for cryogenic liquid containers are foreseen, these rooms must meet the safe-
ty regulations for storing these gases. Attention must be paid when planning these rooms to en-
sure that:
▪ The room's ventilation system guarantees a fresh air exchange rate of at least 1.5 times the
rooms volume per hour
▪ The proper function of the ventilation system is monitored continuously and appropriate
safety precautions are taken to indicate a failure of the ventilation system
▪ Escape routes cannot be blocked by situations in which over- or underpressure may occur
WARNING
Danger to health
People with medical implants or pacemakers may not enter this area. No ferromagnetic parts
may be brought into the area.