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Join Date: Dec 2006
Location: Buenos Aires
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Helium Leak Detectors and Helium requirements

05/17/2007 12:02 PM

Is there anybody who can tell me which requirements must meet the gas Helium to be used with Helium Leak Detector "Adixen (Alcatel) – ASM 142" based on mass spectrometry principle?

Shall I use a gas with some grade of purity, like Helium 5.0, or it can be a common use Helium for globe inflation?

Thank you in advance

Similani

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Pathfinder Tags: helium leak mass spectrometry
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#1

Re: Helium Leak Detectors and Helium requirements

05/17/2007 11:42 PM

any helium should work

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#2

Re: Helium Leak Detectors and Helium requirements

05/18/2007 12:16 AM

I do not think you need high purity.

I presume you are leak testing a vacuum system and blowing helium over joints and other possible leak locations. The leaks will either be sucking in air, if they are large leaks, or if they are very fine leaks only the helium molecules willl get through. Either way it doesn't seem to require exceptional helium quality. And the mass spectrometer is tuned to 'filter' the leaking gas so that the He molecules are the ones that get to its detector.

Greg

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#4
In reply to #2

Re: Helium Leak Detectors and Helium requirements

05/18/2007 11:55 AM

I agree with previous posts.

I would only add that aside from vacuum testing, there are methods of He testing which are done by pressurizing the vessel with He and "sniffing" for helium from the ouside with a sniffer probe. This method is less accurate than the vacuum method which sprays He at the part. We just implemented a He leak test at one of our suppliers.

Typically, you will be measuring the He by flow rates (cc of He/sec) that reach the mass spectrometer. Your testing apparatus has to be linked to this machine by some tubing that is not too small in diameter. If your attachment tubing is too small, the He will have a harder time reaching the mass spect. (Just make sure your tubing isn't very very small like 1/8".)

In my opinion, the most difficult part of the He leak test is your fixturing, because that too must be "helium tight" which can be a challenge depending on your test vessel geometry.

Remember...when your vacuum pump is running a vacuum on the system, DO NOT DISCONNECT THE PART FROM THE SYSTEM!!! This will allow the atmosphere to "rush" into your mass spectrometer and potentially burn up the filiment which then will need service. Always "vent" your system properly to avoid costly delays while your filiment is replaced.

Good Luck,

g

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Active Contributor

Join Date: Dec 2006
Location: Buenos Aires
Posts: 12
#3

Re: Helium Leak Detectors and Helium requirements

05/18/2007 7:42 AM

I am very thankful to Aurizon and Guest for replay. It is very helpful for me.

Similani

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Anonymous Poster
#5

Re: Helium Leak Detectors and Helium requirements

05/18/2007 4:55 PM

Hi there; Helium is helium there-for it should work. It only cost $15.00 at the local party supply house. Used for blowing up balloons; Helium Works well on my classic Veco MS9. Mr X

PS you can use it for laser mix as well.

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