Locking in vnmr

From NMR Wiki

Figure 1. Default view of vnmr Acqi window. Buttons "Insert/Inject" control position of sample. Button "Close" will close the window. Other buttons will allow access to different controls of interactive acquisition.

Figure 2. Lock controls. Buttons "On" and "Off" turn field frequency lock on and off. Data panel with black background shows FID of lock nucleus.

In the vnmr command line type 'acqi' or click 'Acqi' button. A window as shown on Fig. 1 will open. Now click "Lock" button. The window will change into something like you can see on Fig. 2 or 3.

The curve that you see in the window is an FID (free induction decay) of lock nucleus (most often-deuterium).