Methods and Apparatus for Centrifuge Fluid Production and Measurement Using Resistive Cells
A system and method for centrifuge fluid production and measurement using resistive cells is provided. The method comprises separating an electrically conducting first fluid and a second fluid within a collection cell having a first and second section, wherein the collection cell has an electrically conductive outer wall and an inner wall having an insulating material disposed thereon. The method provides that the first and second fluids are separated from a solid disposed in the first section into the second section, the second fluid having a specific mass greater than the first fluid. The method further provides measuring, using one or more wires disposed in the second fluid and electrically connected to a resistance measuring unit within the second section, a resistivity change of the second fluid relative to the displacement of the first fluid, and communicating the resistivity change.
1 . A method for measuring a property of a solid sample, the method comprising:
placing the solid sample in a first section of a collection cell;
separating a first fluid from the solid sample to a second section of the collection cell by rotating the collection cell about an axis of a centrifuge;
displacing a second fluid in the second section of the collection cell with the first fluid separated to the second section, one of the first and second fluids being electrically non-conductive, the other of the first and second fluids being electrically conductive;
measuring a first change in electrical resistance in the second section due to the displacement of the second fluid by the first fluid; and
determining, with the measured first change, the property of the solid sample.
2 . The method of claim 1 , wherein measuring the first change comprises measuring the first change in electrical resistance between at least two first points in the second section of the collection cell in electrical contact with one another through the second fluid in the second section.
3 . The method of claim 2 , wherein measuring the first change in electrical resistance between the at least two first points comprises:
dividing portions of the second fluid, being the electrically conductive fluid, from one another in the second section with an insulated wall; and
passing an electric current between at least one conductor in electrical contact with the second fluid and an electrically resistive contact in electrical contact with the second fluid.
4 . The method of claim 1 , further comprising measuring a second change in electrical resistance in the first section across the solid sample due to the separation of the second fluid from the solid sample.
5 . The method of claim 1 , wherein separating the first fluid from the solid sample in the first section to the second section of the collection cell comprises displacing the first fluid in the solid sample with a third electrically non-conductive fluid invading the solid sample.
6 . The method of claim 1 , wherein separating the first fluid from the solid sample in the first section to the second section comprises at least separating a portion of the second fluid from the solid sample and from the first fluid.
7 . The method of claim 1 , wherein separating the first fluid from the solid sample to the second section of the collection cell comprises separating the first fluid as the electrically conductive fluid from the solid sample; and wherein displacing the second fluid in the second section of the collection cell with the first fluid separated to the second section comprises displacing the second fluid as the electrically non-conductive fluid and invading the solid sample in the first section with the displaced second fluid.
8 . The method of claim 1 , wherein separating the first fluid from the solid sample to the second section of the collection cell comprises separating the first fluid as the electrically non-conductive fluid from the solid sample; and wherein displacing the second fluid in the second section of the collection cell with the first fluid separated to the second section comprises displacing the second fluid as the electrically conductive fluid and invading the solid sample in the first section with the displaced second fluid.
9 . A centrifuge for measuring a property of a solid sample, the centrifuge comprising:
a collection cell rotatable about an axis of the centrifuge;
a first section of the collection cell holding the solid sample;
a second section of the collection cell in communication with the first section;
a non-conductive divider disposed in the second section and dividing portions of an electrically conductive fluid in the second section from one other;
at least one conductor in electrical contact with the electrically conductive fluid;
an electrically resistive contact in electrical contact with the electrically conductive fluid; and
an electrical measurement circuit connected to the at least one conductor and the electrically resistive contact and measuring a value of electrical resistance.
10 . The centrifuge of claim 9 , wherein rotation of the collection cell about the axis separates either the electrically conductive fluid or an electrically non-conductive fluid from the solid sample to the second section.
11 . The centrifuge of claim 10 , wherein displacement of the electrically conductive fluid in the second section due the separation changes the values of the electrical resistance resulting from current passing between the at least one conductor and the electrically resistive contact in electrical contact with one another through the electrically conductive fluid.
12 . The centrifuge of claim 11 , wherein the change in the electrical resistance is indicative of the property of the solid sample.
13 . The centrifuge of claim 9 , further comprising a communication circuit connected to the electrical measurement circuit and communicating information indicative of the value of the electrical resistance.