4137 / Mole (amount of substances): Thermionen-Massenspektrometrie at the PTB in Braunschweig: EUROPA, DEUTSCHLAND, BRAUNSCHWEIG (BRAUNSCHWEIG, GERMANY), 22.11.2007: Thermal Ionisation Mass Spectrometry at Physikalisch-Technische Bundesanstalt PTB in Braunschweig, Germany. Elemental analysis: measuring the amount of a specific element for dissemination of the SI base unit of amount of substance, the mole. Sample solutions are put on sample holders, or filaments, and dried. Attached to a sample wheel, samples are then ionized in the ion source, at front, and extracted at 10.000 V. Ions are then sorted by a magnetic field according to their masses and measured by up to 9 detectors simultaneously. In back: heat-cleaning of used filaments in a vacuum chamber for further use. - Marc Steinmetz / VISUM - Keywords: Germany, science, technology, metrology, base, unit, international, system, of, units, SI, metrical, measure, measurement, standard, lab, chemistry, amount, substance, mole, thermion, mass, spectrometry, ion, ions