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has to alter any of them. The settings for gas groups, range, audio bleep, peak hold and nozzle are
shown on the LCD.
The response of Gas Check can readily be checked against an Ion Science CalCheck. Alternatively the
tracer gas supply can be suitably fitted with an Ion Science Ltd Standard Calibrated Leak.
4.6
Recommended leak search procedure
4.6.1 General procedure
Note: When you use the Gas Check, do not allow dirt or debris to enter the end of the probe or
nozzle. If the probe or nozzle is blocked, the Gas Check will not operate correctly.
The following test procedures assume that you have fitted the short probe. The response time of the
Gas Check increases from about 1 second or less when the short probe is fitted to about 9 seconds
when the long probe is fitted. If you use the long probe for leak detection, ensure that you move the
end of the probe much more slowly along the area you leak test.
Ensure the unit under test contains a reasonable percentage of a trace gas that is different from
normal air!
Move the end of the probe (or nozzle) around the area of a suspected leak and look at the display
(or listen to the audible clicks or note the visual LED flash rate on the Gas Check) to identify the
location of a leak.
Specific procedures for leak detection along seams and around pipe joints are described in the
following sections.
When required:
·
Use the peak hold and Auto-Ranging modes to continue to check for leaks, but to display the
largest leak detected
·
If you want to zero the Gas Check, move the end of the probe (or nozzle) away from any
possible leak, into a clean air zone, then press the manual zero key: refer to Section 4.1.
Note that leak sensitivity depends on the ambient conditions. If you want to accurately measure a
leak, compare the indicated leak with a calibration standard, such as a portable reference leak: see
Section 7.3.
When the Gas Check indicates that a leak has been found, move the probe (or nozzle) back to
determine the precise location of the leak. The leak is located where the largest leak size is indicated
on the display and where highest frequency clicks and visual flashing rate are emitted by the Gas
Check, on the current range.
