66 (107) BRUKER CryoProbe User Manual
Monitoring and Maintenance
Logfile 6.2.2
Logfiles are recorded automatically by the CryoController and periodically stored
on the monitoring computer as auto<yymmdd>.log (yymmdd being the cre-
ation date) in the default directory D:\app\Bruker\CryoTool\LogFiles. For
the diagnosis of problems, your B
RUKER service station will usually ask you to
send a copy of the latest logfile via e-mail.
NOTE: The ‘Elapsed Time’ and the ‘Main pressure’ as of Table 6.2.
cannot be re-
corded in the automatic logfile. Thus, your log-book and the logfile will contain im-
portant complementary information.
Replacement of the He steel-cylinder 6.2.3
0
The He steel-cylinder must be exchanged when its main pressure drops below
30 bar. It is recommended to have a full He steel-cylinder ready by the time the
pressure has come down to 40 bar. With a standard size 50
He steel-cylinder,
there will be still 2-3 warm-up/cool-down cycles possible.
If a 50
He steel-cylinder with an initial pressure of 200 bar lasts for significantly
less than 40 warm-up/cool-down cycles or if the CryoProbe System requires
about one He recharge/week there is a small He leak somewhere. If the long-time
He loss is higher than a preset value, the CryoController will warm-up the system
automatically. See "He leakage" on page 81
.
NOTE: The He steel-cylinder cannot be exchanged (or e.g. used for the magnet’s
LHe refill) while the CryoProbe is in cold operation because the He system would
be inevitably contaminated by air. However, since He is mostly consumed when a
cool-down is initiated, a cold CryoProbe System can run a long time even with an
almost empty He steel-cylinder as long as the He pressure is ≥ 30 bar.
Table 6.3. Replace the He steel-cylinder
step action
b.1 Make sure that the CryoProbe System is W
ARM and in stand-by mode,
i.e.
UNPLUG is lit.
b.2 WARNING: Wear protective glasses when working on pressurized sys-
tems! Do not stand in the direction of any high pressure tube or valve of
the He steel-cylinder.
Close the main valve on the He steel-cylinder but do not change the He
Regulator setting.
b.3 Detach the He Hose from the CryoCooling Unit. Because of the self-
sealing connector, you have to release the remaining pressure from the
He Hose. To do that attach the Dump Tool to the He Hose. You will
hear a hiss from the escaping helium. Wait until all pressure is released.
b.4 Verify that the secondary pressure has dropped to zero and remove the
Dump Tool.
b.5 Detach the He Regulator from the He steel-cylinder but do not change
its valve setting.
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