Helium Background Timer - Agilent Technologies VS Series Operation Manual

VS Series Helium Mass Spectrometer Leak Detectors
External leak:
❑
a. Press VENT to vent the leak detector and then install a calibrated leak into the
system test port.
b. Open the Calibration Set-Up screen and press External Leak (located under
Calibrate With).
c. Press Done.
d. Press Test to place the leak detector into Fine Test mode.
e. Press Control Panel on the Home screen.
The Control Panel appears.
f. Press Calibrate to perform an automated calibration.
For calibration in the E-10 range, the vacuum system must be sufficiently pumped to reduce
helium background below the E-10 range signal level. This is required to achieve an
acceptable signal-to-noise level and ensure accurate calibration.
E-10 range calibration is performed using an external calibrated leak. If an external
calibration is selected soon after system startup, the VS system evaluates the helium
background and determines if the background signal is sufficiently low to give an accurate
calibration. If the:
System has pumped out sufficiently, the calibration proceeds.
❑
Background is changing, indicating the system is still pumping away background
❑
helium, a countdown timer appears (Figure 2-1). The VS system monitors the helium
background and shows the time until the calibration begins. Should you prefer not
to wait, a Cancel button permits the calibration request to be canceled.
2-2
The firmware initially starts at a large time interval, but
NOTE
recalculates the required time as the pumping continues. The
new time is reflected on the timer.
Figure 2-1 Helium Background Timer