Agilent Technologies VS Series Operation Manual page 92

VS Series Helium Mass Spectrometer Leak Detectors
Filament
Gain
To change a manual tuning parameter:
1. Press the desired parameter.
When you press the box containing the desired variable, a highlighted indicator appears
to the right of the numbers.
2. Press the Up or Down arrow to peak the helium signal.
3. Press OK to accept the changes and to store the new parameter value in the leak
detector memory.
4. Press Done to exit the screen and return to the previous menu screen.
3-8
Switches between Filament 1 and 2. The filament selection can be
performed manually, but occurs automatically if the current operat-
ing filament burns out. A calibration routine is recommended every
time the operating filament is changed.
The change appears on the Home and System Information screens
and C flashes on the Home screen to indicate that calibration is
required.
Replace the filament inside the spectrometer as soon as it is
NOTE
convenient after the spare filament has been put into use.
Displays the current value of the Gain of the system. Gain is used
to scale the indicated value of a known leak to agree with a known
correct value. The gain parameter is adjusted after the leak detector
has been tuned to helium. It is automatically set by the Calibrate
Procedure (see Section 2.2.4.1 "Calibration Set-Up" on page 2-17).
Use the value button (next to Gain) to change the Gain value.
Changing Gain changes Zero by the same percentage, which
NOTE
can affect system transfer points.
Typical gain values range from 0.8 to 3.0. The higher the gain,
the more noise shows up in the least sensitive range.
Once a change of value is initiated, you can press Cancel to
NOTE
exit the screen and revert to the original value
Do not press the ESC box before pressing the OK box. This
NOTE
causes the selected parameter to revert to its previously stored
value.