Abstract: Methods and apparatus are provided for detection of large leaks in scaled articles. Apparatus for leak detection includes a first sealable chamber configured to receive a test piece containing a trace gas, a second sealable chamber, a first valve coupled between the first and second chambers, a leak detector having a test port, a trace gas permeable member coupled between the second chamber and the test port of the leak detector, a vacuum pump having an inlet, and a second valve coupled between the second chamber and the inlet of the vacuum pump. The permeable member may be quartz, which is permeable to helium when heated. The leak detector may be an ion pump or a helium mass spectrometer leak detector.

Abstract: Methods and apparatus are provided for leak detection by the accumulation method. The apparatus includes a sealable chamber (10) configured to receive a test piece (12) that, while in the chamber, contains a trace gas, a trace gas permeable member (30) in gas communication with the chamber, and a trace gas sensor (20) in gas communication with the permeable member and configured to sense the trace gas that passed from the chamber through the permeable member. The permeable member may be quartz. The trace gas sensor may include an ion pump.

Abstract: Methods and apparatus for large leak testing are provided. The apparatus includes a test line to receive a sample containing a trace gas, a mass spectrometer to detect the trace gas and having an inlet for receiving the trace gas, a first vacuum pump characterized by a relatively high reverse flow rate for light gases and a relatively low reverse flow rate for heavy gases, the first vacuum pump having a pump inlet and a foreline, the pump inlet being coupled to the inlet of the mass spectrometer, and a second vacuum pump configured to back the first vacuum pump. The apparatus further includes a trace gas permeable member coupled between the test line and the pump inlet, the foreline, or, in the case where the first vacuum pump is a turbomolecular pump, a midstage line.