Inficon Fab UL6000 Fab, Operating Instructions Manual

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6 | Operation INFICON
78 / 152 UL6000-Fab,-PLUS-Operating-instructions-iinc75en1-02-(2207)
6.5 Leak detection with I•RISE (device-dependent)
Standard for UL6000 Fab PLUS.
Introduction
I•RISE performs a leak detector internal cyclic pressure rise measurement.
Leak detection using pressure rise measurement makes use of the fact that a quantity
of gas flows through leaks at a constant rate into a sufficiently evacuated vessel. In
vacuum technology, this vessel is also called a recipient. In most cases, it is a vacuum
chamber.
The advantage to normal helium leak detection is that the total leak rate, i.e. the sum
of all leaks from the recipient, can be measured without spraying. However, only
relatively large leaks can be detected.
For the pressure rise measurement, typically the pump side valve of the evacuated
recipient is closed. Subsequently, a pressure rise in the recipient is usually measured
in mbar/min or Torr/min.
With INFICON's I•RISE solution, the pressure rise is measured in a volume inside the
leak detector and thus outside the recipient.
Compared to a conventional pressure rise measurement, it can be measured much
faster and continuously. A conventional external pressure rise measurement is
replaced by I•RISE.
The leak rate Q can also be determined by multiplying the displayed I•RISE leak rate
by the recipient volume, for example in mbar*l/s:
Q/(mbar*l/s) = I•RISE (mbar/s) * volume/l
Allow I•RISE measurement
ü Operator or supervisor rights, depending on the need for change.
ü
The device is connected to a recipient, for example a vacuum chamber, for vacuum
measurement.
1 Make sure that the device is in the ULTRA measuring mode. See also the
display of the measuring mode in the measuring screen.
ð
In the factory setting, all vacuum ranges are activated and switch
automatically depending on the inlet pressure p1. See also "View vacuum
diagram [
}
92]". The ULTRA measurement range means the highest
sensitivity at low inlet pressures.
ð
If the leak detector does not automatically switch to the ULTRA measurement
range, check that this measurement range has not been deactivated, see
"Activate vacuum ranges [ } 66]" (operator or supervisor rights).
2 Make sure that the turbo molecular pump 2 has started up.