Agilent Technologies VS Series Operation Manual page 135

VS Series Helium Mass Spectrometer Leak Detectors
Command
TUNE
VENT
XYZZY
ZERO
Table A-4 Leak Detection Actions (Continued)
Adjusts the ion source voltage to cause a maximum response to helium.
Causes the leak detector to isolate and vent the test port to the atmosphere.
Unlocks the system so that all RS-232 commands are accessible.
Sets the current leak rate measurement to be 0.0 atm cc/sec in the most
sensitive range.
Action
A-13