INFICON Sensistor ISH2000 Hydrogen Leak Detector - Manual (Page 17)

Hydrogen leak detector Sensistor ISH2000 - Operating Manual
OM-Sensistor ISH2000-EN-201304 17
EN
6 Operating the detector
6.1 To Detect Leaks
If all you wish to do is to detect the presence of a leak, that is, find out whether there is
a leak or not, then use the Locating Mode (or use the Locating bar in Combined
Mode). The definition of Leak/No Leak will then simply be ”A leak is a leak when it can
be detected by the detector, set to a specific sensitivity”.
To set up:
The operation in Locating Mode is not quantitative. The audio and visual signal will
increase and decrease with the gas concentration. Therefore, there is no actual
calibration to be done, but rather a setting of the sensitivity to a desired level.
A typical set-up procedure for Locating Mode is:
•
Set up a Calibration leak which corresponds to the smallest leak you wish to detect.
• Put the probe close to the Calibration leak and note approximately what reaction
you get (no reaction, small, medium, high, full scale) within the first few seconds.
• Set the sensitivity. This can be done permanently under the menu Locating Mode
Settings or temporarily as a Direct Sensitivity Adjustment on the display (unless
you have set this function to OFF under the Locating Mode Settings menu).
There is also an Auto ranging function which can be selected under the Locating
Mode Settings menu.
Note: If the Locating Mode is used and the alarm function is required to be
activated at a particular calibrated level, then the unit must be calibrated in
accordance with the instructions, see “Calibrate the leak detector” on
page 19. The reason for this is that the alarm is based on the Measuring
Mode when the Locating Mode is displayed.
6.2 To Locate Leaks
Note: The Locating Mode (or use the Locating bar in Combined Mode) is used to
locate leaks. This mode is semi-quantitative, that is, it gives an audio and visual
signal which increases as a leak is approached (a higher gas concentration)
and decreases as you move the probe away from the leak. It does not display
figures. In this mode of operation leaks can easily be detected using a
sensitivity which can be preset. See “Sensitivity” on page 28 and “Direct
Sensitivity Adjustment” on page 28.
Leaks can be located very accurately, even when there are other leaks nearby. If, for
example, you are trying to locate a leak on a product and the product has a major
leak, then you will get an audio signal as soon as the probe is placed close to the
product. When the probe is moved around and over the product, the signal will
increase as the probe approaches the leak. If the signal goes out of scale, simply
reduce the sensitivity setting to bring the signal within the scale. Working with the
sensitivity setting this way you will be able to locate multiple leaks that are in close
proximity to each other.
Note: Working inside a confined space such as, for example, a cabinet or a narrow
passage on a combustion engine there is a risk that the background
concentration accumulates to levels close to the upper detection limit of the
detector. In such case it will not be possible to locate leaks as easily as in open
spaces.