Model 979 Series Helium Mass Spectrometer Leak Detector
C-6
DRAFT 9/15/03
C.6.1 Test Piece Evacuated (Figure C-1a and Figure C-1b)
The object to be tested is evacuated by the leak detector roughing pump, then valved into
the spectrometer vacuum system. The surface of the test object is then probed with a small
jet of helium to locate individual leaks, or surrounded by helium (hooded) for an overall
leak check.
Figure C-1a
Test Piece Evacuated: Tracer Probe Used to Locate Leak
Figure C-1b
Test Piece Evacuated and Hooded with Helium Atmosphere to
Determine Overall Leak Rate
C.6.2 Test Piece Pressurized (Figure C-2)
;
Figure C-2
Test Piece Pressurized: Detector Probe Used to Locate Leak
Leak
Detector
Test
Piece
Leak
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Leak
Detector
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Test Piece
Hood
Leak
Leak
Detector
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Leak
Test
Piece
Summary of Contents for 979 Series
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