INFICON Sensistor ISH2000 Hydrogen Leak Detector - Manual (Page 27)

Hydrogen leak detector Sensistor ISH2000 - Operating Manual
OM-Sensistor ISH2000-EN-201304 27
EN
Password Protected Calibration
If desired, the calibration can be set under the general password to prevent the
operator from calibrating by mistake. In this case you will have to enter the
password to start the calibration routine. Setting password protection on calibration
is done in the
General Settings menu. Note that you must also set a password. The
instrument is delivered with no password set.
8.7 Locating Mode Settings
In Locating Mode , the signal is displayed in the form of a bar. The length of the bar
varies with the gas concentration.
To Detect Leaks
If all you wish to do is to detect the presence of a leak, that is, to find out whether
there is a leak or not, then use the Locating Mode. The definition of Leak/No Leak
will 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. No figures are given but the
signal is still increasing and decreasing with 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 the 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
or temporarily as a Direct Sensitivity Setting on the display (unless you have set
this function to OFF under menu Sensitivity Settings . There is also an Auto
ranging function which can be selected under the Locating Mode Settings menu.)
If the sensitivity is set very high, you may find the baseline annoyingly unsteady.
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. The reason
for this is that the alarm is immediately based on the Measuring Mode when
the Locating Mode is displayed, due to inaccuracies in the Locating Mode
signal.
To Locate Leaks
Locating 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. 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 refrigerator condenser tubing
and the tubing has a major leak, then you will get an audio signal as soon as the
probe is placed close to the condenser tubing. When the probe is moved around