Inficon 540-200, Перевод оригинальной инструкции по эксплуатации

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5 | Installation INFICON
26 / 90 T-Guard2_Operating-instructions-jina85en1-13-(2009)
5.2.1 Measurement setup for accumulation measurement
Select the most helium-free environment possible for the measurement setup. For
reliable measurements with the T-Guard2, the helium content in the air must be less
than 10 ppm. By nature, air contains 5 ppm (0.0005%) helium.
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Fig. 9: Measurement setup for accumulation measurements
1 Measurement line 5 Buffer volumes
2 Measuring chamber 6 Fore pump
3 Fan 7 Reference line
4 Test object
• Measurement line
The measuring line and reference line must be the same length.
• Measuring chamber
The measurement chamber must be leak-proof. The net volume, i.e. the
measurement chamber volume minus the volume of the test object, must be
between 0.01 and 10,000 liters. The measurement chamber should not be bigger
than necessary, but the test object may not touch the walls.
• Fan
The measurement chamber must have a fan that blows air at the test object. The
helium or forming gas escaping from the leak is distributed equally in the
measurement chamber by the fan. It is therefore irrelevant from the point of view
of the measurement result whether the leak is close to the measuring line.
• Test object
The test object should not be placed on the areas that may be leaking.
• Buffer volumes