_Studied physics and mathematics at the Technical University of Berlin; Doctor of Science in Physics; Habilitation; _Senior Scientist (retired) of PTB (the German National Metrology Institute); until 2022 Chair of IEC TC 25 ""Quantities and Units""; project leader for the last revision of the ISO/IEC 80000 series of standards in ISO TC 12 ""Quantities and Units"", member for PTB in the BIPM-CCU, expert for ISO and IEC in the JCGM working groups for VIM and GUM; _Author of 5 books, several book chapters, and more than 160 scientific journal articles; _Research Interests: Fundamentals and mathematical methods of metrology, measurement data evaluation, measurement uncertainty, history of mathematics and physics;