Remote leak detection

Claim 1

Improved apparatus for detecting and locating leaks in vessels which have been pressurized with tracer gas of a selected molecular weight, said apparatus being characterized by short response times and the absence of background indications, comprising a. mass spectrometer means for quantitatively detecting and indicating the presence therein of molecules of said tracer gas, said mass spectrometer means having vacuum means For drawing selected atmospheric samples through said mass spectrometer means and for maintaining a suitable vacuum environment therein; b. flexible vacuum conduit means operatively connected to said mass spectrometer means for conducting said selected atmospheric samples thereto; c. a source of a continuous viscous flow of a carrier medium for increasing the capillary conductance of said vacuum conduit and preventing tracer gas hang-up therein, said supply source including flexible carrier conduit means; d. sniffer probe means operatively coupled to said flexible vacuum conduit means and said flexible carrier conduit means for probing the outer surface of the vessel under leak test, said sniffer means comprising sample inlet means for selectively sampling the atmosphere at the outer surface of said vessel for the presence of tracer gas molecules, and carrier inlet means in communication with said flexible carrier conduit means, said sniffer means further comprising a series of passageways leading from said carrier inlet means to said sample inlet means and then to said flexible vacuum conduit means for injecting a carrier medium stream into said vacuum system at a point in proximity to said sample inlet means so that any tracer gas molecules entering with said atmospheric samples will immediately be caught up by said carrier stream and conducted through said vacuum conduit to said spectrometer apparatus in a viscous flow; and e. carrier trap means associated with said mass spectrometer means on the upstream side thereof for removing said carrier medium from said vacuum system upstream of the analytical portion of said mass spectrometer means so that said carrier medium has no effect on the operating environment thereof.