INFICON Sensistor Sentrac Hydrogen Leak Detector - Manual (Page 42)

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8.4 To Quantify Leaks
The Measuring Mode is used for measuring the size of a leak (or the concentration of a
gas sample). To be able to do this measurement and obtain correct values, the
instrument must first be calibrated using the calibration function.
In the Measuring Mode, the detector determines the gas concentration from the
change, as the probe goes from being exposed to background to being exposed to a
certain gas concentration. The detector does not continuously monitor the gas
concentration but takes just one reading. 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 Measuring Mode the probe should be moved directly from a background situation to
the test point. The size of the leak in ppm, or any other selected units, is shown on the
display. The probe can and should be removed from the measuring point as the
measured value steadies and remains on the display. The period during which the
measured value is displayed can be adjusted in the Settings menu.
The leak detector operates in the range 0.5 - 1000 ppm H
₂
. To obtain greatest
accuracy, follow the calibration recommendation. See Chapter 10 “Calibration” on p.
47.