A 400
Testing methods
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02
Sniffer method
(outboard testing)
The test part is pressurized with helium. The detector, via an LDS (Long
Distance Sniffer) probe, samples the helium escaping from the part.
Global test
Local sniffing test
or
He
He
part
LDS
detector
part
detector
LDS
The part is placed under a
cover containing a sniffer
probe.
The leak cannot be located.
The helium from the leak
accumulates over time inside the
cover. The detector measures
the concentration of helium.
The sniffer probe is moved over
areas likely to contain leaks.
The leak can be located.
The signal supplied by the
analyzer is not a direct
measurement of the leak.
The sniffer probe only samples
part of the helium escaping
from the part. The sample
depends on the distance
separating the leak from the tip
of the probe.
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Summary of Contents for ASM 142
Page 1: ...ASM 142 142 D ASM GRAPH GRAPH D GRAPH D HELIUM LEAK DETECTOR User s Manual ...
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