Pfeiffer ASM 340 - Advanced Settings: Operational Modes and Spectro; Massive Mode and Spectro Menu Introduction; Tracer Gas Selection and Calibration

Advanced settings
47
When there is a very gross leak, the detector does not switch to Gross Leak mode and
remains in roughing.
Function activated and pressure < 100 hPa, a message notifies the operator that the de-
tector has switched automatically to massive mode: the detector can then perform a
qualitative leak test (leak information > 5 Pa·m
3
/s (50 mbar·l/s only). The maximum use
time is 55 minutes.
7.5 Spectro Menu
 From the "Settings" screen, press [Spectro].
7.5.1 Tracer gas
The tracer gas is the gas searched for during a test.
3 gases are available:
4
He,
3
He and H
2
.
Calibration The leak detector should be calibrated with a calibrated leak of the same type as the trac-
er gas used.
Hydrogen test The sole purpose of the leak detector is to search for leaks and not to continuously anal-
yse the hydrogen concentration of the pumped gas. The leak detector is not suitable for
continuous analysis of the hydrogen concentration. The operator takes sole responsibil-
ity for using the leak detector in such conditions, as well as for the hydrogen concentra-
tion of the gas used.
The detector's background is higher level of Hydrogen than Helium.
Typical H
2
background, during a test, when the detector is equipped with a blanked-off
flange on the inlet port:
● at switching on: low range ± 1·10
-6
Pa·m
3
/s (1·10
-5
mbar·l/s),
● after 2 or 3 hours: low range ± 1·10
-7
Pa·m
3
/s (1·10
-6
mbar·l/s).
Fig. 26: "Tracer Gas" screen using a function key
From the "Settings" screen, press [Spectro].
Tracer gas  Select the tracer gas used.
For quick access from the control panel, set a function key for [Tracer Gas] (see
7.7.2).