[1] CSIR-National Physical Laboratory India (CSIR-NPLI), Dr. K. S. Krishnan Marg, New Delhi
[2] National Institute of Metrology, Thailand (NIMT), 3/4-5 Moo 3, Klong 5, Klong Luang, Pathumthani
[3] National Metrology Centre (NMC), Agency for Science, Technology and Research (A, STAR), 1 Science Park Drive, Singapore
[4] Bundesamt fuer Eich- und Vermessungswesen (BEV), Arltgasse 35, Wien
[5] National Metrology Institute of Japan (NMIJ/AIST), Tsukuba Central 3, 1-1-1, Umezono, Ibaraki, Tsukuba