INFICON UL5000 Dry Helium Leak Detector User Manual
Page 73
Description of the Menu
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Maximum evacuation time
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> Maximun evacuation time
This menu item is used to define when the gross leak message is to occur. The gross
leak detection process operates in two steps and the limits can be adapted as
required.
This menu item is particularly useful in series testing under the same conditions at
all times.
After pressing the start button the test sample is evacuated. If the pressure condi-
tions (p1 < 100 mbar) are not attained, or if the pressure does not drop low enough
within the periods of time specified here, the pumpdown process is terminated and
the display will indicate a message (see 8.2, W76).
The periods which are selected in each case depend firstly on the desired reaction
time for the gross leak message, and secondly on the volume of the test sample and
the effective pumping speed.
Caution: If the evacuation time was set to endless, the oil level of the mechanical
pump should be checked more often.
Softkey No. 2:
Decreasing maximum evacuation time until p1 < 100 mbar. Within this period of time
the inlet pressure at the test flange must have dropped below 100 mbar. The
duration may be selected freely between 1 second and 9 minutes or can be set to
endless. The default is 30 seconds.
Softkey No. 3:
Decreasing maximum time until measurement Within the period of this time the
status of measurement readiness must have been attained, i.e. the inlet pressure
must have dropped below 15 mbar. The duration may be freely selected between 5
seconds and 30 minutes or can be set to endless.
Softkey No. 5:
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Help text
Softkey No. 6:
Increasing maximum evacuation time until p1 < 100 mbar
Softkey No. 7
Increasing maximum time until measurement.