Re: cpm conversion to mrem/hr

["James G. Barnes" <mail15077@pop.net>]

Actually, one does see such conversions from time to time.  They are generally 
treated as "rules of thumb."  Examples can be found in IAEA #152, "Evaluation 
of Radiation Emergencies and Accidents."  Granted, such relationships are not 
scientifically rigorous, but they are very handy to get a feel for what one is 
dealing with.

Your comments regarding calibration are correct.  How does one equate two 
measurements that use different geometries (i.e., calibration setups vs. 
"field" measurements).  CPM to mr/hr can be done, but one must be very careful 
to ensure that the field measurement duplicates the geometry of the calibration 
setup.

As to your comment regarding sarcasm. . . .we have a saying in the U.S. that 
there is no "stupid" question.  Given that we all use various thumb rules in 
day to day health physics, I don't think that the question was all that 
off-base.  Are you possibly just laying on the flame button a little heavily?


Jim Barnes, CHP
Radiation Safety Officer
Rocketdyne Division; Rockwell Aerospace

    > At 13:49 28.08.1996 -0500, you wrote:
    > >I was looking through some x-ray diffraction reports and ran across
    > >some conversion figure converting cpm from a GM to mR/hr or mrem/hr.  I
    > >can't remember where I saw it.  Anyone no what it is?
    > >
    > >David Harrison
    > >DHARRISON@DOE.LANL.GOV
    > >=========================================================================
    > =
    > 
    > I cannot believe that you saw anything like this, because the conversion 
    > is
    > dependent on your GM, on the energy of the radiation and probably a couple
    > of other conditions. In fact calibration would have to be done 
    > individually. 
    > 
    > Is this the expertise which DOE employees have?
    > 
    > Anybody who wants to accuse me of the typical European arrogancy is
    > requested to refrain from it. I had so many positive responses on my
    > sometimes sarcastic comments to my private e-mail that I do not care for 
    > the
    > one or two who do not like it. 
    > 
    > Instead I would recommend that you Americans would do something to rise 
    > the
    > average scientific level of your health physics people. I know that you 
    > have
    > a large number of excellent experts, which are among the best in the world
    > and I am honoured to know some of these personally. But this is not enough
    > for everyday life. 
    > 
    > Franz Schoenhofer
    > Schoenhofer
    > Habichergasse 31/7
    > A-1160 WIEN
    > AUSTRIA/EUROPE
    > Tel./Fax: +43-1-4955308
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    > e-mail:       schoenho@via.at
    > 
    >