INFICON LDS3000 Modular Leak Detector - Manual (Page 19)

Installation 19
5.3 Connecting the mass spectrometer module to the test system
The operation mode of the vacuum connection and the speed of the turbo molecular
pump define:
• Minimum detectable leak rate (MDLR)
• Maximum inlet pressure (P
max
)
• Volume flow rate (S)
* constantly permissible inlet pressure
Temporary exceed (< 3 s):
Permissible inlet pressure is 0.4 mbar in U
LTRA and 0.7 mbar in F INE .
Long-term exceed (> 3 s):
Warning (TMP overheating) and possible damage to the filament.
1 Set the operation mode vacuum connection and the speed turbo molecular pump
in accordance with the physical vacuum conditions found in the test system.
2 Connect the mass spectrometer module to the U LTRA , F INE or G ROSS connections
on the vacuum system of the test system.
3 Set the speed of the turbo molecular pump.
Connection Speed turbo molecular pump
1000 Hz 1500 Hz
U LTRA
MDLR: < 5 x 10
-12
mbar·l/s < 1 x 10
-11
mbar·l/s
P
max
: 0.2 mbar 0.2 mbar *
S: 5 l/s 6 l/s
F INE
MDLR: < 1 x 10
-11
mbar·l/s < 5 x 10
-11
mbar·l/s
P
max
: 0.9 mbar 0.4 mbar *
S: 1.8 l/s 2.5 l/s
G ROSS
MDLR: < 1 x 10
-9
mbar·l/s < 2 x 10
-8
mbar·l/s
P
max
: 18 mbar 15 mbar
S: depends on the backing pump
Material damage due to pressure surges
Pressure surges exceeding the maximum inlet pressure will damage the mass
spectrometer module.
► Do not exceed the maximum inlet pressure.