Agilent Technologies Helium Leak Detector
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B.3.2 Pressure Testing Method (Inside-out)
In this technique, the part is pressurized with helium or a mixture of helium and air, and
tested by one of the following methods.
B.3.2.1 Measuring Leaks
To determine the total quantity of leakage (but not the number or location of leaks), the part
is pressurized with helium (or a mixture of helium and air or nitrogen). This can be done by
bombing or backfilling small hermetically sealed parts. Larger parts can be actively
pressurized using a hose or tubing to deliver the helium. The part is placed in a volume that
is then evacuated by the leak detector. All the helium escaping from the part is captured and
quantified (Figure B-5).
Figure B-5 Measuring Leaks: Inside Out
B.3.2.2 Locating Leaks
To pinpoint the location of the leak(s) (but not measure the total leakage), the likely potential
leak sites of the part are scanned using a Sniffer Probe connected to the inlet of the leak
detector (Figure B-6).
Figure B-6 Locating Leaks: Inside Out
Mount Test Part
to Port
Mount Test Part
to Port
