Table of Contents
Advertisement
N O T E
N O T E
N O T E
Cryogenic Systems Operation
Close the CryoBay Controls popup window after the
3
cryogenic operation begins. The status changes to
Vacuum Pumping. The status of the cryogenic system
and Agilent Cold Probe is checked through the CryoBay
Main window. Fault messages are listed in the VnmrJ
Error Bar.
The status changes to Cooling and purging begins after
4
Vacuum Pumping. The helium cylinder valve may be
closed when purging is complete after the system status
changes to Cooling and the compressor has started.
The system status says Cooling while the system is purging. Once the
system completes purging, it starts the compressor and begins the
cool-down sequence.
Most helium regulators leak to some degree. Failure to close the valve may
cause the helium cylinder pressure to decrease significantly over time.
a. Close the valve on the helium cylinder.
b. Close the helium regulator valves.
5
Tighten the side- arm coupling nut on the cryogenic
transfer arm periodically during cool- down. Adjust the
nut at approximately 100 K and 30 K, or roughly every
30 minutes.
Failure to tighten the coupling nut may cause the system to fail to cool
down to the set point. The system will automatically warm up if it has not
reached the set point after 8 hours.
The system is ready for NMR when the status changes to
6
Operating.
Under normal operating conditions the system will be
ready for use in approximately 4 hours.
and NMR stability is achieved when the system is
allowed to equilibrate overnight.
Continue with tuning the Agilent Cold Probe as described
7
in the Agilent Cold Probe Installation manual.
2
Cryogenic Operation
Optimal system
29
Advertisement
Table of Contents
