Patent ID: 8137642
Filing Date: 2012-03-20
Classification: G01N

Abstract:
1. A method of calibrating a bubble point of a filter and liquid combination, comprising: (a) dispensing the liquid into a container, wherein the filter forms a surface of the container in contact with the liquid; (b) applying an initial back pressure through the filter toward the liquid; (c) taking a first plurality of measurements of a level of the liquid in the container; (d) calculating a first variance of the first plurality of measurements; (e) comparing the calculated first variance of the first plurality of measurements with a known threshold variance; (f) taking a second plurality of measurements of a level of the liquid in the container; (g) calculating a second variance of the second plurality of measurements; (h) comparing the calculated second variance of the second plurality of measurements with the known threshold variance; (i) incrementally increasing the applied back pressure; (j) repeating steps (c) to (i) until the calculated first and second variances are each greater than or equal to the known threshold variance; and (k) identifying the bubble point as the back pressure when the calculated first and second variances are each greater than or equal to the known threshold variance.