On inelastic X-ray scattering experiment (IXS), we published the measurement results of Au and Pt in international papers. These were constituted only using the bulk modulus obtained by IXS and the X ray lattice constant data measured at the same time; thus they are recognized as the primary pressure scale. After that, we succeeded in measuring the single crystal elasticity of NaCl up to 20 GPa and Ta up to ~33 GPa.
On the other hand, on the GHz sound velocity method, it took long time to acquire the signal from the DAC sample. However by introducing ammonia coating, metal coupler, devising new DAC support, and developing S-wave buffer rod, the simultaneous P-wave and S-wave of the iron sample was finally obtained at 2 GPa.