Patent ID: 8762079

Claim:
A computer implemented method of estimating characteristic geometric parameters of a double-walled cryogenic tank having a cylindrical portion that is insulated with or without vacuum comprising: a step of measuring the pressure differential (in Pa) between the top and bottom parts of the tank before a filling (DP mes — before ) using a pressure sensor; a step of measuring the pressure differential (in Pa) between the top and bottom parts of the tank after said filling (DP mes — after ) using the pressure sensor; a step of determining the mass of liquid delivered (m delivered ) (in kg) during said filling; and a step of calculating, using a computer processor, a radius (R) of the cylindrical portion, the tank comprising at least one end that has an elliptical portion of set height (F), said radius (R) being calculated from: the mass of liquid delivered (m delivered ) (in kg) determined during the filling; the difference between the pressure differentials (DP mes ) measured before and after filling (DP mes — after −DP mes — before ); and the densities of the gas and of the liquid (ρ g , ρ l ) in the tank, the radius (R) (in m) is calculated using the equation: R = m delivered ⁢ g ⁡ [ 1 - ( MAVO ) ] π ⁡ ( DP mes_after - DP mes_before ) in which the pressure differentials are expressed in Pa, π is the number Pi, g is the acceleration due to gravity of the Earth (in m/s 2 ) and MAVO is a dimensionless corrective coefficient that is a function of the density.