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The point is that under the reasonable units, 1 Roentgen = ~ 1 rad in tissue.
Thus, a meter which reads in mR/hr also, for purposes of radiation protection,
reads in mrad/hr. If we are forced into SI units, this major operational
convenience would be lost.
The opinions expressed are strictly mine.
It's not about dose, it's about trust.
Curies (and rads) forever.
Bill Lipton
liptonw@dteenergy.com
"Jean-Francois, Stephane" wrote:
I
thought Roentgen would apply to X-rays in air only ? No matter what
you read, you would need a conversion if you apply that to something else
then air ? I fail to see the point.Also
since g, the gravitationnal constant is the same pretty much everywhere
I go, I am expressing my weight in Kg or Lbs, not in Newtons.
Stéphane
Jean-François, Eng.,
CHP,
Spécialiste
en radioprotection-Radiation Safety Specialist
Gestion des
risques-Risk Management
Merck Frosst
Canada et Cie,
514.428.8695
Fax:514.428.8670
stephane_jeanfrancois@merck.com
http://www.merckfrosstlab.ca
A
question for the pro-SI crowd.How
do you reconcile using a standard ion chamber type radiation detector that
reads out in microSv / hr, and recording that reading as the exposure level?(I
hope your answer doesn’t include a discussion of quality factors.Regardless
of what you may know about beta & gamma radiation, the meter ain’t
displaying microSv / hr)
I
think this is my main discomfort with using SI units in that there is no
useful conversion for Roentgens.If
you are TRULY a proponent of SI, you should have a meter that reads out
in Coulombs / kg-hr (or metric subunits thereof), and then try to work
with that unwieldy number.Or else
only use tissue equivalent meters.
-Brent
Rogers
P.S.How
many of you express your weight in Newtons?
-----Original
Message-----
From:
Ivor Surveyor [mailto:isurveyor@vianet.net.au]
Sent:
Tuesday, 8 April 2003 6:38 PM
To:
radsafe@list.vanderbilt.edu
Subject:
Subject: RE: Bq soon
To
a person living outside of the USA it is a matter of amazement to find
the bizarre combination of units used in American texts. For instance
on a single page of a recently published text on Radiation Protection [
J. Shapiro 4th Edition] I found the student had to contend with a plethora
of units.
On page 361:
Ft; Ft^2; Ft/min; Ft^3/min; cm^3/day; pCi/cc; microCi/cc;
mCi; MBq
Or on page 372: 1 acre = 4,047 m^2; 1km^2
= 247 Acres; pCi/m^2-s
and a reminder to multiple mCi by 37 to obtain
MBq, and pCi by 0.037 to convert to Bq; or Ci by 37 to obtain GBq.
Though out the book there is a continuous need
to convert Sv to rem(s); Gy to rad(s); length in cm, ft or m and
so on.
By the way in strict SI there is no place for
the cm, cc, or cm^3. or use of "pleural forms for units.
I just wonder
how this irrational jumble of old and new units is tolerated.
Surely more then one "Mars probe" must have gone astray, because
of this confusing jumble? I suspect that more then one author
has developed a severe "headache" from proof reading of texts. The
high quality of many American texts and publications are such as
to have a great appeal to international readers
What a waste of intellectual effort is expanded in converting backwards
and forwards from one system to the other, as one reads and studies papers,
text books, or regulations.
I am not aware of any real problem in Australia
or UK when we adopted the SI system, except perhaps a feeling of joyous
relief.
Ivor
Surveyor [isurveyor@vianet.net.au]
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