Waters GCT Premier Operator's Manual page 302

EI Tune tab parameters: (Continued)
Parameter
Filament Off
Emission Current
(µA)
Ion Repeller
B-24 The MassLynx Tune window
Description
Click the button to switch the filament on and off.
This enables you to leave the instrument for a long
time without the filament burning out or sagging.
In filament save mode (Filament Off), the button
changes to Reset Filament.
The instrument also defaults to the into filament
save mode after a sample list acquisition. The fila-
ment stays off until Reset Filament is clicked, or
another acquisition is started.
A measurement of the electrons emitted by the
filament, including those that hit the trap. This
value can be used to diagnose problems. For
example, if the ratio of emission to trap is more
than 4:1, the inner source is likely dirty or the fila-
ment is misaligned.
A plate in the inner source that repels the ions out
of the inner source towards the focusing lenses. Set
this value to between 0 and 1. As the source
becomes dirty, the value needs to be increased. If
you increase the value to more than 5 V, you may
need to clean the source.
See also: Cleaning the trap and repeller on
page 10-23.