Re: Swipe Testing

[Christian Schoenhofer <schoenho@via.at>]

Schoenhofer
Habichergasse 31/7
A-1160 Wien
AUSTRIA
Tel./Fax: +43-1-4955308
Mobiltel.: +43-664-3380333
e-mail: schoenho@via.at
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>         As Franz (I think) is alluding to - if you add unknown/unusual
> factors like toilet paper (the coloring and aroma/scent etc.) or a shirt
> with color(s)/detergents etc., can cause many confounding factors to your
> LSC analysis...(hence the MCA first).
> 
>         Happy counting,
> 
>         Joel
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Joel,

I hope you did not understand my comment wrong. From your mails I see that
you know exactly what you are doing. Instead of wasting time and money, I
would use any material for swipe tests which is reachable. Paper,
fabric,.....
As long as you do not introduce chlorine, deep colours etc. an experienced
person will be able to interpret an LSC- spectrum even if it would not be
in colour. And this is the point - one needs to be experienced. There is no
doubt, that in a laboratory where only tritium is used, it is not necessary
to tear apart ones shirt for swipe tests. It is not necessary to perform a
gamma-analysis either. I hardly believe that anybody would put a swipe on
his/her HPGe-system. For any experienced person this is clear. If you test
for leakage of a Ni-63 source, you will not use your HPGe-system. If your
contamination monitor goes off in the middle of nowhere and everybody tells
you that nobody ever worked there with radioactive material I am almost
certain you will use any material for swipe tests and the first you  h a v
e  to do is a gamma-analysis. 

Gross contamination is not gross contamination. Tritium is somewhat
different than Sr-90, even the so called most poisonous substance plutonium
is nothing compared with the ("naturally occurring and therefore healthy")
radium. 

I conclude that simple tests can be performed by rather unexperienced
persons, but in cases of unknown radionuclide contamination only well
experienced persons and well equipped laboratories should perform the swipe
tests and the analyses. For a well equipped laboratory high resolution
gamma spectrometry is simply a must. 

Franz