Re: Gamma/LSC counter calibration

[Schoenhofer <schoenho@via.at>]

At 08:42 19.06.1998 -0500, you wrote:
>OK, 
>I got an easy one for you guys, I hope.
>I am trying to calibrate my LSC and my gamma counter for Cr51 
>efficiency WITHOUT a Cr51 standard. In doing so,  I took 
>some Cr51 waste, counted it in the gamma counter, took the same 
>waste, counted it in the LSC, and obtained nearly the SAME results in 
>each counter. BUT, my Packard poster says that I should obtain ~10 
>times as many counts in the LSC as in the gamma.  
>SO, are the efficiencies of each counter the same? Do other labs get 
>the same result? Am I overlooking something? Please fill me in before 
>I send off for a standard.
>You may reply to me personally in case I did something really 
>embarassing.
>
>Steve G.
>
>----------------------------------------------

Steve,

Everything depends on what you want to do. If you want to do precise
measurements then you will not be able to avoid to buy a (traceable)
standard. If you want to do approximate measurements then your approach
will be acceptable - if your gamma counter is calibrated well. Do not rely
on what companies tell you. 

We had a long time ago the problem of finding Cr-51 in surface water of a
little river. We did all measurements with HPGe-detectors and though we are
well specialized in LSC I never got the idea to use LSC for this
determination. 

Franz


Franz Schoenhofer
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