Abstract: A leak detector is adapted to test the fluid-tight sealed integrity of a hermetically-sealed package having a movable wall portion. An enclosure surrounds a package-to-be-tested, and the space within the enclosure is evacuated by a vacuum pump. As the pressure acting on the outer surface of the package begins to fall,the gas within the package will be expand, pushing the movable wall portion outwardly. Such displacement of the movable wall portion is sensed and compared with a predetermined value. If desired, the reduced pressure within the enclosure may be held constant for as time interval, and the sensor used to determine whether the distended wall portion has relaxed.

Abstract: A vacuum package tester is capable of providing data by which the internal pressure and volume of residual gas of a flexible wall vacuum package exposed to atmospheric pressure may be calculated. A container partially filled with liquid is surrounded by a deformation-absorbing enclosure. A vacuum pump reduces the pressure in the head space above the liquid, thereby causing a submerged package to expand. Pressure gauges record the respective pressures in the head space when the package expands by first and second known volumes. From this data, the internal pressure and volume of residual gas of said package, when exposed to ambient pressure and temperature, may be calculated. In use, the invention also performs an improved method.