Impedance layer estimation

A system for estimating the impedances of layers (Li, Lj) on electrodes in an annular, circular symmetric, multiphase pipe flow, comprising a pipe including a set of electrodes (I, j) being evenly distributed along the inner pipe circumference, the electrodes being connected to measuring instrument for measuring the impedance between each electrode and the other electrodes obtaining a set of impedance values Rijmeasured, the flow in average being annular, circular symmetric,

• the system also including a computer with a computer storage including a precomputed model defining a solution space Rijflow of expected impedance values and for which the conductivity a depends only on r and increases as r increases, r being the radius away from the center of the flow,
• wherein
• Rijmeasured=Rijflow+Li+Lj=(Rijflow−2k)+(Li+k)+(Ljk), (equation 2)
• k, being a variable and the impedances Fijflow being categorized depending on the distance between the measuring electrodes (i, j) in order to reduce the number of unknowns in equation 2,
• the system further being configured to finding impedances of the layers (Li, Lj) on the electrodes and adding various k to the layers' impedances (Li, Lj) such that the impedances of the layers (Li, Lj) combined with an average of the measured impedances over a chosen period places the resulting averaged impedances within the boundary of the pre-computed solution space Rijflow, representing the expected impedance value range.