VSE knjižnice (vzajemna bibliografsko-kataložna baza podatkov COBIB.SI)
  • Evaluation of cross-float measurements with pressure balances - results of EURAMET project 1125
    Morgado, Isabelle ...
    The calibration of a pressure balance is usually carried out by applying the cross-floating method which is based on the equilibrium of the pressures applied on two piston-cylinder assemblies. It ... involves determining values of the zero-pressure effective area (A[sub]0) and the pressure distortion coefficient ([lambda]) that define the pressure dependent effective area (A[sub]p) of the piston-cylinder assembly (PCA). There are various approaches to determine these parameters and to estimate their uncertainties, with results that may differ significantly. A recent revision of the EURAMET guide for the calibration of pressure balances has raised this matter and demonstrated the need of recommendations to harmonize the calculation methods for determination of A[sub]0, [lambda] and their uncertainties, which is the objective of EURAMET project 1125. The idea is to compare the performance of the calculation methods used by the NMIs. In order to compare it, theoretical values of the parameters have been fixed arbitrarily for four cases: two for a gas calibration up to 10 MPa and two for an oil calibration up to 500 MPa. Considering these values, calibration data sets have been generated: some random and systematic errors have been added, and additional masses needed to reach the cross-floating equilibrium have been calculated. The generated data sets, which included the description of the cross-floated PCAs, mass pieces, environmental conditions and properties of the fluids, have been provided to the project participants. Each participant has calculated A[sub]0, [lambda], A[sub]p and their uncertainties using its own method. The results are compared with the theoretical values in order to evaluate the appropriateness of the different methods and to make recommendations. Besides describing the participants' calculation methods, this paper presents the results of the comparison considering the theoretical values as reference values.
    Vir: 5th CCM international conference on pressure and vacuum metrology : in conjuction with the 4th international conference IMEKO TC16, Berlin, May 2-5, 2011 : abstracts (Str. 17-18)
    Vrsta gradiva - prispevek na konferenci
    Leto - 2011
    Jezik - angleški
    COBISS.SI-ID - 867754

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