Report on the reference densities of water and air employed for the adjustment of vibrating tube density meter

0504773 - ÚT 2020 RIV CZ eng V - Research Report
Vinš, Václav - Prokopová, Olga
Report on the reference densities of water and air employed for the adjustment of vibrating tube density meter.
Praha: Ústav termomechaniky AV ČR, v. v. i., 2019. 15 s.
R&D Projects: GA ČR(CZ) GA19-05696S
Institutional support: RVO:61388998
Keywords : vibrating tube densimeter * calibration * density * equation of state
OECD category: Thermodynamics

The report summarizes accurate models for densities of pure water and humid air at atmospheric pressure which are needed for temperature calibration of the vibrating tube densimeter, particularly Anton Paar DMA 5000 M. For an accurate calibration of the instrument, several technical issues have to be addressed. This report serves as a basis for a discussion with the representatives of company Anton Paar. Using the Matlab software, several algorithms were developed for calculation of water density using (i) Wagner and Prüß (2002) equation of state IAPWS-95, (ii) Tanaka et al. (2001) CIPM standard, and (iii) Spieweck and Bettin (1992) mathematical formulation. In accordance with the guideline IAPWS G8-10, a humid air model was programmed based on the dry-air equation of state by Lemmon et al. (2000) and the IAPWS-95 equation for water vapor. The results for humid air were compared with the CIPM standard by Picard et al. (2008) and a simplified mathematical formulation from Spieweck and Bettin (1992). The final part presents density data for pure water measured in the Laboratory of Thermophysical Properties in the temperature range from 2 to 50 ° C for various reference relationship settings of the water and humid air densities considered in the instrument calibration.

Permanent Link: http://hdl.handle.net/11104/0298377