Operation
GA10218_002_A7 - 9/2015 - © Oerlikon Leybold
73
For the use of a PHOENIX L300i with a Quicktest the setting for the Quicktest
under Main menu > Settings > Monitoring functions > Pressure limits for sniff mode
has to be chosen.
Machine factor
Main menu > Settings > Vacuum settings > Machine factor
The machine factor takes into account, after an internal calibration, the ratio
between the effective helium pumping rate of the PHOENIX L300i and the pumps
in the pump system in measurement mode as well as the measurement mode
used (GROSS/FINE).Based on an internal calibration only, all measured leak rate
would be measured too small. The measured leak rate is multiplied with the
machine factor and the result is displayed. This factor is only used for vacuum
measurement modes (not for sniff mode). See Numerical entries for the description
of the entry.
Since the effective pumping rates are usually not known due to the conductances
of the vacuum connections, we recommend the following indirect measurement:
1. Set up the PHOENIX L300i for operation
2. First an internal calibration must be performed with machine factor = 1 (Refer to
Chapter 7)
3. Connect an external calibrated leak (for example 2.0·10
-6
mbar l/s) to the test
chamber
4. Measure leak rate of the external test leak, for example
5.0·10
-8
mbar l/ s
5. The machine factor is the quotient of the desired value and the actual value.
Desired value: 2.0·10
-6
mbar l/ s / 5.0·10
-8
mbar l/ s = machine factor 40
6. Set the acquired value in the menu point
7. Calibrate again internally so that the machine factor is taken over
8. All signals that are measured in further measurements are multiplied by factor 40
and then shown in the display
Leak rate internal test leak
Main menu > Settings > Vacuum settings > Leak rate internal test leak
The value of the internal test leak can be set. See Numerical entries for the descrip-
tion of the entry.
Normally there is no reason to edit the leak rate of the internal test leak besides
after a change or a recertification of the internal test leak. A wrong leak rate of the
internal test leak will lead to wrong leak rate readings!
Purge in measurement
Main menu > Settings > Vacuum settings > Purge in measurement
Softkey 4: Set default value
Setting between the default value 1 for the sniffer line SL300 or the cor-
rection factor (1000) for the use of the Quicktest.
Quicktest setting
Machine factor
Leak rate internal test leak
Purge in measurement
