INFICON UL1000 Helium leak detector - Manual (Page 40)

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Description and Working Principle
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Besides maintaining the pressure in the mass spectrometer the pump system is used
to evacuate the test parts. It is made sure that the pressure in the mass spectrometer
is low enough under all circumstances. The valves V1a, V1b, V2, V4a, V4b control
the gas flows when measuring. Valves V5 (only UL1000), V6, and V8 are used to
vent the system and the Turbo pump. Valve V7 opens and closes the internal test
leak during calibration.
With the pressure in the test part being lower than ambient pressure sprayed helium
can penetrate into the part in case of a leakage. As soon as the pressure conditions
allow it one of the valves to the TMP opens. Now Helium can penetrate into the mass
spectrometer contrary to the pumping direction of the TMP.
See Chapter 4.3 Working Modes for details.
4.2.2 Control Panel
The Control Panel Fig. 4-2 /7 contains a liquid chrystal display (LC Display), the
START, STOP, ZERO and MENU buttons and also eight Soft Keys for the different
menus and inputs.
The control panel itself is rotable.
Fig. 4-2: Control Panel
Pos. Description Pos. Description
1 LC Display 8 Soft Key no. 5
2 Soft Key no. 1 9 Soft Key no. 6
3 Soft Key no. 2 10 Soft Key no. 7
4 Soft Key no. 3 11 Soft Key no. 8
5 Soft Key no. 4 12 MENU Button
6 START Button 13 STOP Button
7 Control Panel 14 ZERO Button