Patent ID: 7945395
Filing Date: 2011-05-17
Classification: G01N

Abstract:
1. Method for determining the density of a liquid by density meters with a flexural oscillator holding the liquid to be measured therein on the basis of measuring periods of oscillation at two different natural vibrations of the flexural oscillator and of at least a vibration damping value at one of the natural vibrations to find out whether air inclusions and/or other inhomogeneities are present in the liquid or not to decide if the measured density value is correct or not, the method comprising: (a) determining the periods of oscillation of the flexural oscillator when filled with inclusion-free samples of different densities ρ and viscosities η at two different natural vibrations and of at least one characteristic vibration damping value δ at one of the natural vibrations, (b) calculating from the measured period values at the natural vibration having the lower frequency the density values ρ (c) calculating a functional dependence (δ,Δρ  in which the density values ρ (d) expanding the inclusion-free curve KB to provide an inclusion-free curve area KF having a deviation bandwidth on both sides of the curve KB and a constant distance in a direction normal to the curve KB, (e) storing the inclusion-free curve area KF, (f) for each subsequent liquid sample the density of which is to be measured with the flexural oscillator, determining the actual functional value (δ,Δρ (g) testing whether the actual functional value F (δ,Δρ