Currently, I am an Assistant Professor of Physics at New Mexico Highlands University. A TIF picture of my ultrafast pulsed femtosecond laser laboratory can be found here.
Pressure is measured by the standard ruby fluorescence technique.
In particular, the metallic gaskets that are typically used for confining samples under high pressure shield radio frequency electromagnetic fields to and from the sample. This necessitates the use of extensive signal averaging and spin echo techniques. A new technique has been developed to load liquid hydrogen inside the NMR cryostat which allows us to keep the sample at low temperatures at all times. The ortho-para conversion of hydrogen using NMR was measured up to 128kbar for my Ph.D. thesis. This should serve to give us confidence that high pressure NMR research using diamond anvil cells can go into the megabar regime with further improvements.