Patent ID: 8393209

Claim:
A capacitive detector comprising: a ribbon made of a dielectric material; at least one pair of electrodes including a first electrode in the form of a comb formed on a first surface of said ribbon and including parallel transverse branches interconnected by a longitudinal connection branch and a second electrode in the form of a comb formed on said first surface of said ribbon and including parallel transverse branches interconnected by a longitudinal connection branch, the transverse branches of said first and second electrodes being disposed alternately between one another according to at least one determined period (λ); and a third electrode in the form of a layer formed on the other surface of said ribbon opposite said first and second electrodes; wherein the thickness (e) of the dielectric ribbon is less than or equal to said determined period (λ) divided by four times PI; and that the ratio resulting from the division, as numerator, of the capacitance (C) between two adjacent branches of said first and second electrodes in the presence of at least one fluid with a dielectric permittivity (∈ f ) and, as denominator, by the dielectric permittivity (∈ f ) of the fluid multiplied by the capacitance (C o ) between the two adjacent branches of the first and second electrodes in the presence of the vacuum is greater than or equal to one.