Patent ID: 6082174
Filing Date: 2000-07-04
Classification: G01N

Abstract:
An assembly for measuring an amount of entrapped gas in a material sample in a test environment, comprising:(a) a reservoir configured to receive the material sample, said reservoir having first and second sections, said second section being adjustable in position relative to the first section from a first position to a second position such that the reservoir has an adjustable volume from a first volume to a second volume, respectively, when the material sample is received within the reservoir and a predetermined pressure which is negative relative to atmospheric pressure in the test environment is applied to the reservoir, the position of the second section relative to the first section being indicative of the volume of the reservoir;(b) a detector coupled to said second section and configured to measure the position of the second section relative to the first section;(c) a processor which is coupled to the detector and which is configured to determine an amount of entrapped gas within the material sample received within the reservoir based upon a change in the position of the second section from the first position to the second position; and(d) a vacuum chamber enclosing said reservoir and configured to apply said negative pressure to said reservoir;(e) wherein said material sample expands in response to application of said negative pressure to said reservoir,(f) wherein the first volume of the reservoir is substantially equal to the volume of the material sample at atmospheric pressure in the test environment,(g) wherein the second volume of the reservoir is substantially equal to the volume of the material sample when the material sample expands after applying the negative pressure to the reservoir, and(h) wherein the differential between said second volume of said reservoir and said first volume of said reservoir is indicative of the amount of gas entrapped in said material sample.