Patent ID: 8146421

Claim:
An apparatus for measuring discrete heights of at least two insoluble fluids, said apparatus comprising: at least two main capacitive sensors having distinct geometries; and wherein said geometries of said sensors satisfy the following equation: C A = ɛ 0 ⁢ ɛ a ⁢ ∫ 0 z a ⁢ w A ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ 0 z a ⁢ d A ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z a ] + ɛ 0 ⁢ ɛ b ⁢ ∫ z a z b ⁢ w A ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ z a z b ⁢ d A ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z b - z a ] ⁢ ⁢ … ⁢ ⁢ ɛ 0 ⁢ ɛ n ⁢ ∫ z n - 1 z n ⁢ w A ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ z n - 1 z n ⁢ d A ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z n - z n - 1 ] C B = ɛ 0 ⁢ ɛ a ⁢ ∫ 0 z a ⁢ w B ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ 0 z a ⁢ d B ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z a ] + ɛ 0 ⁢ ɛ b ⁢ ∫ z a z b ⁢ w B ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ z a z b ⁢ d B ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z b - z a ] ⁢ ⁢ … ⁢ ⁢ ɛ 0 ⁢ ɛ n ⁢ ∫ z n - 1 z n ⁢ w B ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ z n - 1 z n ⁢ d B ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z n - z n - 1 ] C N = ɛ 0 ⁢ ɛ a ⁢ ∫ 0 z a ⁢ w N ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ 0 z a ⁢ d N ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z a ] + ɛ 0 ⁢ ɛ b ⁢ ∫ z a z b ⁢ w N ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ z a z b ⁢ d N ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z b - z a ] ⁢ ⁢ … ⁢ ⁢ ɛ 0 ⁢ ɛ n ⁢ ∫ z n - 1 z n ⁢ w N ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z [ ∫ z n - 1 z n ⁢ d N ⁡ ( x , y , z ) ⁢ ⁢ ⅆ z z n - z n - 1 ] provided the following constraints are true: N>=n AND(w A (x,y,z)≠C* w B (x,y,z)≠ . . . ≠D*w N (x,y,z) for all real C, D AND/OR d A (x,y,z)≠F*d B (x,y,z)≠ . . . ≠G*d N (x,y,z) for all real F and G, so that w A (x,y,z), w B (x,y,z), . . . w N (x,y,z) are independent equations, and d A (x,y,z), d B (x,y,z), d N (x,y,z) are independent equations.