Method for the calculation of fluid interface level

A method for calculating the boundary layer level between fluids, in particular the boundary layer level between oil and water in connection with the use of a segment-based boundary layer meter. The calculations are based on the use of measurement signals from a number of segments, n, and the boundary layer level, L, of the water is calculated as follows: L=[(P-Po)/(Pv-Po)]*(Lu-Ll)+Llwhere: Lu Upper water range area (*), LlLower water range area (*), Pn Density of segment no. n from the profile meter, ñ Pn Corrected density for segment no. n, P Calculated mean density, Pv Mean density of water from the profile meter, Po Mean density of oil from the profile meter, N Total number of segments included.