tracer-gas leak testing

Several tracer-gas leak testing methods exist, including:

• Detection of leaks using helium mass spectrometer, which provides high sensitivity
• Hydrogen leak testing, which provides the best mobility
• Refrigerant gas leak detection, for refrigeration applications

The nature of the product or the process and the process gases will set the leak rate requirement:

class="wikitable" !System !Allowed leak rate (mbar L/s)

Chemical process equipment |10−1–1

Beverage can |10−5 –10−6

Vacuum pumped system |10−5–10−7

IC-package |10−7–10−8

Airbag cartridge |10−8

Pacemaker |10−9

Closed vacuum system |10−9

Based on the target leak rate, the table below will help to choose the most suitable method.{{Cite news|url=http://www.vicleakdetection.com/global-engineers-of-airvacuumtracer-gas-leak-detection-systems/leak-detection-sensitivity-guide/|title=Leak Detection Sensitivity Guide - VIC Leak Detection|work=VIC Leak Detection|access-date=2017-06-15|language=en-US}}

class="wikitable" !Method !Sensitivity (leak rate in mbar l/s)

Ultrasonics |10−1|10−1

Bubble test in water |10−2

Pressure decay |10−2

Vacuum decay |10−2

Acoustic emission detectors |10−3

Bubble test in soapy water |10−4

Gas-specific thermal conductivity detector |10−5

Halogen detector |10−5

Photoacoustic spectroscopy |10−6

Hydrogen sniffer |10−6

Residual gas analyser |10−7

Dye penetrant |10−8

Radioactive tracer |10−10

Helium mass spectrometry vacuum testing |10−11

Typical applications of tracer-gas leak testing include:

• In petrochemical plants, hydrocracking, vapocracking, catalytic reforming, and steam reforming are all hydrogen-based processes, in which were hydrogen leak testing is required.
• When manufacturing semiconductors, all processes taking place in a process chamber at atmospheric pressure or under vacuum – diffusion, oxidation, LPCVD, PECVD, PVD and ion implantation – require helium or hydrogen leak testing.
• In vehicles, airbags have to be tested for leaks so they remain functional for a long time. As well as airbags, the air conditioning system, fuel system, and exhaust system require testing for leaks.
• Pacemakers and catheters have to be tested for efficacy and longevity.
• On planes, tracer-gas leak testing is used to quickly and safely locate fuel leaks,{{Cite news|url=https://www.theguardian.com/afghanistan/story/0,,2209288,00.html|title=MoD accused over spy plane deaths|last=Townsend|first=Mark|date=2007-11-11|work=The Guardian|access-date=2017-06-15|last2=correspondent|first2=defence|language=en-GB|issn=0261-3077}} as well as to check oxygen distribution devices and cabin pressurization systems.
• Refrigeration and air conditioning must have the lowest possible rate of loss of refrigerant gases (contributing to ozone depletion).
• Sewage and drinking water networks, to reduce loss of water and make sure drinking water is not contaminated by sewage.

{{See also|Leak detection#Rules and regulations}}

Several standards apply to leak testing and more specifically to tracer-gas leak testing methods, for example:

• BS EN 1779:1999; leak tightness by indication or measurement of gas leakage,
• BS EN 13185:2001 Non-destructive testing. Leak testing. Tracer gas method,
• BS EN 13192:2002 Non-destructive testing. Leak testing. Calibration of reference leaks for gases.

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Category:Tests

Category:Nondestructive testing

Category:Hydrogen technologies