Split Flow Operation Or Parallel Pump Operation - Agilent Technologies VS Series Operation Manual

2.3.15 Split Flow Operation or Parallel Pump Operation

The VS-C15 takes into account split flow operation where a considerable amount of helium
signal can be diverted away from the mass spectrometer caused by parallel pumping, which
is necessary for rapid test cycles. An external calibration to a calibrated leak connected to
the test chamber is highly recommended. External gain calculations, up to a split flow factor
of 150, can be obtained for proper characterization of the leak test system.
When large split conditions are present, with large external gain factors, a Range Stop is
implemented for up to two decades of operation.
Access this screen via the Setup Menu (2nd level):
Split Flow Activation
2-56
VS Series Component Leak Detector
Figure 2-28 Split Flow
This feature is available February 2011.
NOTE
This feature is very helpful for those customers (integrators) who
only perform an internal calibration. If an external calibration is
not performed the internal calibration gain is applied to the system
gain. Typically the internal and external calibrations are the same
(within 20%) but this not the case for large roughing/test pumps.