INFICON UL1000 Helium leak detector - Manual (Page 74)

74
Description of the Menu
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6.6.3 Mass
• Main Menu > Settings > Mass
The requested mass of the measured gas can be selected. The UL1000 and UL1000
Fab must be in Stand-by.
Softkey 2: Zero at ULTRA
With “Zero at ULTRA” the ZERO functions executes automatically as soon as the
measuring range ULTRA is reched for the first time after START. In this mode the
ZERO function also can be executed manually via the ZERO button.
Softkey 3: Disable: ZERO function
Softkey 5: Help
Softkey 6: I•Zero
The Zero function is locked as long as the leak rate signal is not stable enough to
detect a leak of the programmed value of Trigger 1.
The function „I•Zero“ enables the ZERO button only at stable leak rate signals. This
is displayed in the status bar through the STABLE signal.
By the standard Zero function the actual background value will subtracted when
pressing ZERO. At falling background signals smaller leaks could be missed
because the subtracted background value is higher than the leakrate signal at the
moment of measuring.
By „I•Zero“ the drift of the falling background signal is checked, if it is higher than
0.5 x trigger value 1 (adjusted to the desired rejection level).
If I•Zero function is active, the configured trigger value 1 is displayed.
Softkey 7: Enable: ZERO function
Softkey 2: H
2
(2 amu)
Hydrogen with the mass of 2 amu will be measured.
Softkey 3:
3
He (3 amu)
Isotop of helium with the mass of 3 amu will be measured.
Softkey 7:
4
He (4 amu)
Helium with the mass of 4 amu will be measured.