Varian UNITY INOVA NMR, Hardware Installation, Page: 10 / 65

SAFETY PRECAUTIONS
01-999044-00 C0501 UNITY INOVA Solids Hardware Installation
9
Warning Notices ( continued )
WARNING:
Support the magnet and prevent it from tipping over.
The magnet dewar has a high center of gravity and could tip over in an
earthquake or after being struck by a large object, injuring personnel and
causing sudden, dangerous release of nitrogen and helium gasses from the
dewar. Therefore, the magnet must be supported by at least one of two methods:
with ropes suspended from the ceiling or with the antivibration legs bolted to
the floor. Refer to the
Installation Planning Manual for details.
WARNING:
Do not remove the relief valves on the vent tubes.
The relief valves prevent air from entering the nitrogen and helium vent tubes.
Air that enters the magnet contains moisture that can freeze, causing blockage
of the vent tubes and possibly extensive damage to the magnet. It could also
cause a sudden dangerous release of nitrogen and helium gases from the dewar.
Except when transferring nitrogen or helium, be certain that the relief valves are
secured on the vent tubes.
WARNING:
On magnets with removable quench tubes, keep the tubes in place
except during helium servicing.
On Varian 200- and 300-MHz 54-mm magnets only, the dewar includes
removable helium vent tubes. If the magnet dewar should quench (sudden
appearance of gases from the top of the dewar) and the vent tubes are not in
place, the helium gas would be partially vented sideways, possibly injuring the
skin and eyes of personnel beside the magnet. During helium servicing, when
the tubes must be removed, carefully follow the instructions and safety
precautions given in the manual supplied with the magnet.
Caution Notices
Observe the following precautions during installation, operation, maintenance, and repair
of the instrument. Failure to comply with these cautions, or with specific cautions elsewhere
in Varian manuals, violates safety standards of design, manufacturing, and intended use of
the instrument. Varian assumes no liability for customer failure to comply with these
precautions.
CAUTION:
Keep magnetic media, ATM and credit cards, and watches outside the
5-gauss perimeter from the centerline of the magnet.
The strong magnetic field surrounding a superconducting magnet can erase
magnetic media such as floppy disks and tapes. The field can also damage the
strip of magnetic media found on credit cards, automatic teller machine (ATM)
cards, and similar plastic cards. Many wrist and pocket watches are also
susceptible to damage from intense magnetism.
Refer to the manuals supplied with the magnet for the size of a typical 5-gauss
stray field. This gauss level should be checked after the magnet is installed.