INFICON UL1000 Helium leak detector - Manual (Page 47)

Description and Working Principle
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4.3.2 Sniffer Mode
In sniff mode a sniffer line (preferably the INFICON standard sniffer line 14005) is
connected to the inlet port. When pressing the
START Button the system starts to
pump air through the sniffer line. Due to the constant gas flow through the sniffer line
the software will range directly into FINE mode and stay there. The inlet pressure will
not drop further down. By measuring the inlet pressure the system software makes
sure that the flow through the sniffer line is at the right level. Otherwise warning
messages are generated. The detection limit in sniff mode is <1×10
-7
mbar l/s.
INFICON’s sniffersystem QT100 may also be used to sniff. Since the QT100
provides a lower inlet pressure it is recommended to keep the system in vacuum
mode to avoid a wrong generation of pressure warnings. The machine factor has to
be adjusted to value 400.
4.3.3 Auto Leak Test Mode
In this mode the test of hermetically sealed testing objects can be performed
automatically. By use of the optional test chamber TC1000 this test mode starts
automatically when closing the chamber lid. Fast test results within seconds are
achieved by using the internal test leak of the UL1000 or UL1000 Fab for a dynamic
calibration, matched to the required test cycle. Leak rates in the 10-9 mbar l/s range
can be detected within 5 seconds.