Re: RE: GM Response (formerly Respect)

[LIPTONW@dteenergy.com]

I believe that calibration source certifications are usually corrected for 
backscatter, although you should read the fine print carefully.  Such a 
corrected certification probably states the "apparent" 2 pi activity.  Then, 
if your source also has backscatter, you then have to correct for that in 
assaying the source. 
 
The opinions expressed are strictly mine. 
It's not about dose, it's about trust. 
 
Bill Lipton 
liptonw@dteenergy.com  
 
You wrote: 
 
<Bill: 
 
<One quick question: I'm a fan of Knoll, but don't suppliers of NIST sources 
<take the backing material into account when they give the 4 pi dpm values? 
<If your detector and source have the same area, should it matter? Having 
<said that, I've seen mysteriously different efficiencies when using a 12
cm2 
<source to calibrate large-faced (126 cm2) detectors on different surface 
<types. 
 
<Jim Herrold 
<Radiation Safety Officer 
<University of Wyoming 
 
herrold@uwyo.edu
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html