Patent ID: 8513958

Claim:
A stacked sensor for testing a porous medium, comprising: a plurality of porous ceramic elements, wherein each element operates as a discrete variable capacitor, each element exhibits a different known liquid release curve, and each element comprises a first axial opening, and wherein the elements are stacked one on top of another such that the radial axis of each element is positioned along a common axis; a first number of electrically conductive interface plates, wherein each plate comprises a second axial opening, and the first number is one greater than the total quantity of elements, and wherein the plates are axially distributed within the sensor such that, the radial axis of each plate is positioned along the common axis, the first axial openings of the elements combine with the second axial openings of the plates to form a longitudinal cavity within the sensor which is centered along the common axis and extends from a proximal end of the sensor to a distal end of the sensor, and each element is sandwiched between a different pair of plates such that substantial electrical contact is established between the element and both plates in the pair; and a second number of electrical conductors, wherein the second number equals the first number, a distal end of each conductor is electrically attached to a different one of the plates, and a proximal end of each conductor is routed through the cavity to the proximal end of the sensor.