Models 947, 948 and 960 Leak Detectors Operations and Service Manual
3-8
TRANSFER POINTS
Set the test transfer pressures for each testing mode.
The transfer pressure settings can be adjusted to lower
values for specific applications. The 947/948/960 has
pre-programmed upper transfer pressure limits that are
slightly greater than the default settings. These limits
prevent the operator from inadvertently setting the
947/948/960 to transfer into test at too high a pressure,
resulting in excessive spectrometer tube contamination or
ion source filament failure.
GROSS LEAK XFER
The GROSS LEAK XFER set point determines the test
pressure cross over point at which the 947/948/960
transfers into the GROSS LEAK TEST mode. In the GROSS
LEAK TEST mode, the majority of the sampled gas is
pumped away through the dedicated roughing pump while
a small sample of gas is introduced into the leak detector
through a throttle valve.
