Abstract: A method of measuring fluid leakage around or through a barrier. In the preferred embodiment, the leakage measured was around a permanent mine stopping. To make the measurements a temporary test stopping with two windows was erected near the permanent stopping under observation. It is not necessary that the test stopping be leak-free. The first of the two windows has a known cross-section area and the second window also has a known cross-section area. To practice our invention, an anemometer is used to measure the flow through the first hole before the second hole or window is opened. Then the flow through this same window is measured when both holes are open. Next, the flow through the second hole is measured when both holes are open. Using these three measurements and the principles of fluid dynamics, the total leakage past the permanent stopping can be mathematically determined.

Abstract: A helical open ended tube is rotated so as to pass an open end successively through two different fluid media. Successive slugs, first one and then the other, of the media are captured, screwed along the length of the tube and retained therein for subsequent analysis.