Progress in the realization of a practical pressure scale for the range 1-300 GPa

X-ray diffraction measurements on diamond and various metals under hydrostatic pressures up to similar to 140 GPa together with determinations of ruby luminescence line shifts provide new constraints for the refinement of a practical pressure scale based on either the ruby line shift or the X-ray diffraction with the given calibrants. Implications for other high-pressure studies with diamond anvil pressure cells as well as for theoretical high-pressure studies and for equation of state forms are discussed.