Waters Xevo G2 QTof Operator's, Overview And Maintenance Manual page 56

22. Using the nebulizer adjuster knob, adjust the capillary so that it
protrudes by approximately 0.5 mm from the end of the probe tip.
During normal operation, the adjuster knob relies on gas pressure
Tip:
to retract the capillary. To retract the capillary without gas connected,
invert the probe and use gravity.
23. Fit the end-cover and gasket to the probe assembly.
Nebulizer adjuster knob
3-12 Configuring the LockSpray Source
Gasket
End-cover