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Water & air calibration of vibrating-tube densimeter at temperatures from 0 to 90 °C and atmospheric pressure
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SYSNO ASEP 0543772 Druh ASEP C - Konferenční příspěvek (mezinárodní konf.) Zařazení RIV O - Ostatní Název Water & air calibration of vibrating-tube densimeter at temperatures from 0 to 90 °C and atmospheric pressure Tvůrce(i) Prokopová, Olga (UT-L)
Blahut, Aleš (UT-L) RID, ORCID
Čenský, Miroslav (UT-L)
Součková, Monika (UT-L) RID, ORCID
Vinš, Václav (UT-L) RID, ORCIDCelkový počet autorů 5 Číslo článku 4054 Zdroj.dok. 21st Symposium on Thermophysical Properties. - Boulder, Colorado, 2021 Poč.str. 18 s. Forma vydání Online - E Akce Symposium on Thermophysical Properties /21./ Datum konání 20.06.2021 - 25.06.2021 Místo konání Boulder, Colorado Země US - Spojené státy americké Typ akce WRD Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova fluid density ; uncertainty ; vibrating tube densimeter ; water Vědní obor RIV BJ - Termodynamika Obor OECD Thermodynamics CEP GA19-05696S GA ČR - Grantová agentura ČR Institucionální podpora UT-L - RVO:61388998 Anotace Vibrating tube densimeter (VTD) is a popular instrument providing quick and relatively accurate measurement of density for large variety of liquids and gases [May et al. Rev. Sci. Instrum. 85 (2014), Fortin et al. J. Chem. Thermodynamics 57 (2013)]. The commercial instruments have resolution of down to 0.001 kg/m3 and their accuracy is declared to reach 0.007 kg/m3 under ideal conditions at temperatures close to ambient. However to our experience, the uncertainty of the obtained data can be significantly higher than the accuracy stated by the manufacturers when it comes to measurements over wider temperature range.
In this work, we present thorough calibration procedure for a commercial borosilicate glass VTD (Anton Paar DMA 5000M) over wide temperature range from 0 to 90 °C. The approach is similar to that of Fritz et al. [J. Phys. Chem. B 104 (2000)] when the density can be obtained from the relative oscillation period PQ and two calibration constants A and B as: density = A*PQ^2 – B. Temperature dependencies of the calibration constants A and B and the damping of dry air were determined from a series of precise measurements with dry air and ultrapure water correlated to the densities calculated from the IAPWS-95 equation of state for water and in terms of the IAPWS G8-10 guideline for humid air. The calibration procedure is verified on measurements of several pure liquids, namely toluene, ethanol, ethylene glycol, and glycerol. A detailed analysis of the uncertainty budget resulted in the standard uncertainty below 0.03 kg/m3 for typical low-viscosity samples. In case of highly viscous liquids such as low-temperature ethylene glycol or glycerol, the uncertainty can reach 0.06 kg/m3 or even 0.15 kg/m3 at the viscosity exceeding 600 mPa.s, respectively. These results are considerably different from the manufacturer’s typical declarations. Additional influences such as relation between the liquid viscosity and the damping, the isotopic composition of the employed ultrapure water, the measurement procedure covering VTD cleaning and filling are also discussed.
Pracoviště Ústav termomechaniky Kontakt Marie Kajprová, kajprova@it.cas.cz, Tel.: 266 053 154 ; Jana Lahovská, jaja@it.cas.cz, Tel.: 266 053 823 Rok sběru 2022 Elektronická adresa https://thermosymposium.org/
Počet záznamů: 1