INFICON Extrima Ex-certified Hydrogen Leak Detector - Manual (Page 14)

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EN
INFICON - Operating Instructions EXTRIMA
Basic leak detection
Extrima has three different modes: Detec-
tion Mode, Analysis Mode and Combined
Mode. The Combined Mode is the default
mode.
In Detection Mode you will see a bar and
hear a sound with a frequency that in-
creases as the probe approaches the leak,
and decreases as the probe is moved away
from the leak. No figures are shown on
the display, and the frequency is not an
accurate measure of the leak rate.
You will soon get used to listening for
changes in the frequency rather than to
the actual frequency. Move the probe
over the surface of the tested object to
detect and precisely locate a leak, even
when there are other leaks nearby. Keep
moving the probe to find out where the
signal increases and where it decreases.
Let the audio signal guide you to the
exact position of the leak.
If you expose the probe to a constant
gas concentration you will hear the fre-
quency continue to increase slowly until
it eventually levels off, and very slowly
declines again. This takes 30 - 45 seconds
for small leaks and just a few seconds for
large leaks. The decline is the automatic
background adjustment coming into ac-
tion. A gas concentration being constant
for several minutes is being taken as an
increased background level.
In Analysis Mode figures are shown on
the display. These figures are an accurate
measurement of the leak rate.
The detector determines the gas concen-
tration from the change as the probe
goes from being exposed to background
to being position right on the leak.
The detector does not continuously mo-
nitor the gas concentration but takes just
one reading instead. Another suitable
alternative name for this mode could be
Sampling Mode. It is important to keep
this in mind when using the detector in
this mode.
In Combined Mode the bar and the sound
in Detection Mode is combined with the
figures in Analysis Mode, this means that
at the same the signal is displayed as a
bar and the measured value is displayed
in figures.
When you have located the leak you can
measure its size in the following way:
1. Remove the probe from the leak into
fresh air.
2. Wait until 0.0 appears on screen and
then put the tip of the probe right
on the leak.
NOTE: The tip of the hand probe
gets warm when the instrument
is in use. This is normal.
!
CAUTION!
Always connect the probe before
switching on the instrument.
Never put the probe in water or
any other liquid.