Bruker BioSpin Solid State NMR, User Manual

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32 (327) BRUKER BIOSPIN User Manual Version 002
General Hardware Setup
Safety precautions involve flushing the probe frame, this serves to keep the
tuning elements at decent temperatures. Furthermore, the magnet must be
kept at legal temperatures to prevent freezing of O-rings or excessive ex-
pansion of the inner bore tube. The shim stack must be kept at tempera-
tures below 70 °C, else the shim coils might be damaged. With MAS probes,
it must be made sure that no wet air is sucked into the eject tube, which
would lead to formation of ice on low temperature runs. This requires to
maintain some overpressure above the spinner (usually by applying some
flow to the insert gas line).
Heat exchangers must be dried with a flow of dry gas before use, so there is no
water left in which will ice up the exchanger loop. After use, they must be warmed
up and dried with a dry gas flow so that there is no water in leading to corrosion.
The following figures show the various connections to different probes.
Figure 3.21. WB Probe MAS VTN and WVT, and DVT Probe Connections
1. Probe heater connector
2. VT gas in 3. TC connector (s)
4. Frame flush gas