What the Libra zodiac sign is all about: Libra is the seventh of the 12 zodiac signs, which begins its cycle in early fall every year during Libra seasonâwhich falls around September 23-October 22.
How it works. This schematic shows the component parts of a typical leak-down tester. The gauge on the right is held at a standard pressure by adjusting the pressure regulator while the gauge on the left shows an example reading of 85-or 15% leakage.
HOW IT WORKS. 1  The portable, hand-operated PosiTest AIR Leak Tester tests the air barrier integrity of single, two-ply and liquid membrane systems, including air barriers, roofing systems, waterproofing and ground liners by locating leaks. 2  In accordance with ASTM E1186, the PosiTest AIR will indicate whether leaks exist in the test area.