2.2 Ceiling Height
01-999021-00 A0100
Installation Planning Guide
15
2.2 Ceiling Height
The ceiling must provide
sufficient headroom to insert
the liquid-helium transfer
tube into the magnet dewar
and the storage dewar. The
height of the ceiling (or that
part of the ceiling located
directly above the magnet)
without obstructions, such as
lighting and heating ducts,
must be equal to or greater
than the minimum heights in
.
These ceiling minimums
allow enough headroom to
insert the standard helium
flutter tube and refill transfer
tubes into the magnet dewar.
They also allow use of the standard power stick for running up the magnet field. If one of
the larger capacity liquid-helium storage dewars is used with the magnet, however,
additional ceiling clearance may be necessary. In general, the ceiling height must be at least
twice the height of liquid helium storage dewar above the floor. Oxford magnets can be
provided with optional hinged top-loading components that reduces the minimum ceiling
height requirements. Contact Oxford for details.
Most of the antivibration (vibration isolation) systems do not change the ceiling height
requirements, except the 200/54 and 300/54 magnets or any magnet with both the sample
changer and an antivibration system. In these cases, add 20 cm (8 in.) to the ceiling height
requirements.
2.3 Accessibility
The site must also provide adequate access for the routine delivery of supply dewars
containing liquid helium and nitrogen.
2.4 Maximum Altitude
The maximum altitude during operation is 2440 m (8000 ft). The maximum during storage
or transport is 9100 m (30,000 ft).
2.5 Structural Strength of Floor
Contact a plant engineer, structural engineer, or registered civil engineer to confirm that the
magnet does not exceed the structural floor loading rating. The site floor must have
sufficient structural strength to support the combined weight of the spectrometer system
and moving equipment used during installation.
list shipping weights and dimensions.
list the weights and dimensions
of the system components after they are installed.
Table 5. Ceiling Height Minimum
Magnet Type*
(MHz/mm)
Ceiling Minimum
cm (in.)
With Optional
Helium Level Sensor
cm (in.)
200/54
225 (89.4)
236 (93)
200/54 LH235
314 (124)
314 (124)
200/54 LH365
314 (124)
314 (124)
300/54
225 (89.4)
236 (93)
300/54 LH235
314 (124)
314 (124)
300/54 LH365
314 (124)
314 (124)
400/54
314 (124)
314 (124)
400/54 LH365
314 (124)
314 (124)
* Long-hold magnets are designated by “LH” and a
number that represents hold time in days.