PTB_LOGO_RGBPTB is the German nation metrology institute and the highest technical authority in metrology and some areas of safety engineering in Germany. It has some 1600 employees, a third of which are researchers and engineers with university degrees.
The working group “thermal state behaviour and density” is in charge to measure the volume, density and mass of the sinker which is used to measure the density of LNG. PTB participates in this JRP because of its internationally acknowledged experience and excellence in density measurements, proven by the organisation of and participation in key comparisons and the cooperation in the International Avogadro Project. For the density measurements, CMC entries in the BIPM database exist.
The working group “caloric quantities” is basically concerned with research and development of thermodynamics and calorimetry. There exists a sound expertise in combustion calorimetry among others based on a long term experience in pattern approval of calorimeters and in providing measurement services to customers. Recent research is, among others, concerned with gas calorimetry with special focus on biogas.

Key publications are:

  • H. Bettin, H. Toth, “Solid density determination by the pressure-of-flotation method,” Meas. Sci. Technol., vol. 17 (2006) pp. 2567-2573.
  • H. Bettin, H. Toth, “Density Determination of a Small Isotopically Enriched Silicon Single Crystal,” IEEE Trans. Instrum. Meas., vol. 56 (2007) pp. 257 – 261.
  • P. Schley, M. Beck, M. Uhrig, S. M. Sarge, J. Rauch, F. Haloua, J. R. Filtz, B. Hay, M. Yakoubi, J. Escande, A. Benito, P. L. Cremonesi, “Measurements of the Calorific Value of Methane with the New GERG Reference Calorimeter,” 17th Symposium of Thermophysical Prop., Boulder, CO, 21-26 June 2009, published in International Journal of Thermophysics 31 (2010) 665 – 679.