Book excerpt: M. Kochsiek, M. Glaser (eds.) Comprehensive Mass Metrology Mass determination is of fundamental importance for science, technology and economics. Technical measuring systems range from ultramicro balances to weighing machines for freight trains; massive objects range from subatomic particles to galaxies. Comprehensive and topical, this reference work -- edited by scientists of the Physikalisch-Technische Bundesanstalt, Germany -- covers the whole field of mass determination. Starting from physical foundations, it describes virtually all measurement techniques in detail and gives a thorough overview over scientific experiments related to the determination of masses. Reports on contemporary problems, such as a new definition of the kilogram, historical excursions and a list of references without competition make this book an absolute must for everyone dealing with questions relating to mass determination in fundamental research, technical application, calibration service, and standardization. From the contents: - Mass as a Physical Quantity - The Determination of Mass - Mass Comparators - Quantities Derived from Mass and their Determination