Bruker NMR iProbe HR-Liquids, User Manual, Page: 41 / 56

Operation
Z33146_1_001 41 / 56
Figure 7.23: Standard Bore (SB) Shim System – View from Bottom
a Projection of the
laboratory frame’s Z’-axis φ1 Angle between X-axis Boss2/3 shim system and
projection of laboratory frame’s Z’-axis
b X-axis Boss2/3 shim
system φ2 Angle between X-axis Boss1 shim system and
projection of laboratory frame’s Z’-axis
c X-axis Boss1 shim
system
7.6.6.2 Shimming in the TopShim Manual Mode
Samples with a strong signal like H
2
O are recommended for initial shimming. The sample
must be rotating at a reasonable spinning rate.
• Set all shim values to 0 (BSMS panel or using setsh in TopSpin).
• Load the corresponding lock solvent with lopo . The lock should now be in sweep mode
and the lock wiggles should be visible. Otherwise adapt Field and Gain accordingly.
However, the lock wiggles will probably be too broad for locking.
• Run topshim changemasshims and set the angle when asked for according to Table 7.3
[ } 40]
Figure 7.24: TopShim pop-up window, where the angle phi has to be entered.
• (Use the command topshim calreset to reset the angle phi.)
• Optimize the Z’ shim until locking is successful by using rather large steps (e.g. 1’000
units).