Abstract: A leak detector for sensing a test gas leaking into a vacuum chamber in accordance with this invention comprises a vacuum chamber having an opening, and a momentum transfer pump connected to such opening and serving to compress the gases emanating from the vacuum chamber. An entrainment pump is connected to receive the gases exhausted from the momentum transfer pump, with the entrainment pump having means for entrapping the active exhaust gases coming from the vacuum chamber, but not the noble gases, which remain in a gaseous state and continually increase in pressure. A mass spectrometer is connected to receive the output from the entrainment pump, with the entrapment of the active exhaust gas by the entrainment pump reducing the total pressure at the mass spectrometer gas detector, thus making possible the detection and measurement by the mass detector of extremely small noble gas leaks.

Abstract: An apparatus and process designed for detecting both large and small leaks in components, such as the hermetic seals of electronic components, especially small components. The small component leak detector comprises (i) a container means such as a glove box maintained at about one atmosphere pressure for receiving test objects, (ii) a movable probe situated with the glove box for sniffing and capturing samples of detecting gas in proximity to the test object, (iii) an entrainment pump which consists of a getter pump or a modified cryopump located between the sampling probe and the mass detector for measuring the detecting gas, and (iv) a mass detector. The entrainment pump is capable of entrapping a purge carrier gas, such as nitrogen, but not entrapping a detecting gas, such as helium.

Abstract: A small component leak detector is provided having (i) a vacuum chamber for receiving test objects, (ii) a cryogenic pump, and (iii) a mass detector. The cryogenic pump is capable of entrapping a purge carrier gas, such as nitrogen, but not entrapping a detecting gas, such as helium. The purge carrier gas is entrapped by the cryogenic pump and the mass detector detects any helium emitting from the test object. The process of detecting leaks using the foregoing apparatus in conjunction with a purge carrier gas, such as nitrogen, is also disclosed and claimed. The apparatus and process are especially designed for detecting leaks in small components, such as the hermetic seals of electronic components.

Abstract: A process of calibrating an ultrasensitive noble gas leak detector using a radioactive alpha source, such as americium 241, comprising accumulating helium molecules from the radioactive alpha source in an enclosed volume for a specified period of time, permitting the helium molecules to enter a vacuum chamber, and obtaining a gas detection measurement to calibrate the detector for the sensitivity of the system.

Abstract: A noble gas leak detector is provided using a non-evaporable getter pump to remove active gases but not noble gases during leak detection. The vacuum system is constructed of all-metal valves, metal connection devices and metal passageways to reduce out gassing and minimize the permeation of helium into the system. Valves are appropriately located to seal off unnecessary devices during the actual leak detection. In addition, a process of calibrating a noble gas leak detector is provided using americium 241 alpha as the calibrating source.