Use of the "I" gas line option
For ASM 180 TD and ASM 180 TD+
2/11
C 70
Edition 03 - May 97
Alcatel Vacuum Technology France - ASM 180 TD/TD+ - ASM 181 TD+ User’s Manual
Operating
principle
Test principle
The detector is connected at the 1/4 VRC connection to
one end of the line under test.
The carrier gas is injected at the other end of the line.
The line is pumped by the detector and the carrier gas is
injected to obtain a laminar flow (a few mbar absolute
pressure).
Helium is sprayed around the line.
In the event of a leak, the helium which enters the line is
"transported" to the detector by the carrier gas.
The sensitivity of the test depends on the helium content of
the carrier gas (which must be as low as possible).
He
N
2
1
2
3
4
3
5 6
6
8
9
9
10
7
1. Detector inlet port
2. Gas line inlet port
(VCR connector)
3. St. steel flexible connector
4. Rigid line under test
5. Reference leak
6. Manual valve
7. Mass flow controller (N
2
)
8. Flexible connector
9. Pressure controller
10. Helium spray