[ RadSafe ] Adopting the International System of Units for Radiation Measurements in the United States: Proceedings of a Workshop

Mon Mar 6 11:56:55 CST 2017

"I have yet to see an cabinet x-ray leakage limit correctly specified in a
MEASURABLE 35.8 pico C/Kg.sec - to go COMPLETELY SI (I hope I got that
right)."

I think the one of best talks there was done by someone who did take the
time to point out there's no such thing as a "pure SI" system that is
universally used for absolutely everything and exclusive for all situations.

For example, in "pure SI," there is "no such unit of time besides
seconds."  Do you see many Europeans researchers/scientists/public figures
talking about what they did 31 1/5 million seconds or so ago?  And Celsius
is not the SI unit for temperature, kelvin is, but kelvin is just not
practical for most "ordinary" purposes.

And even here we tend to play mix 'em up with units.  Especially in
medicine, where we use (milli)liters and grams for so much but connect them
to RAM measured in units of Curies or play the Gy and pounds game.

I'd put that talk near the top, as it was an emphasis that this doesn't
have to be a line in the sand, either/or, pick a side and fight to the
death kind of battle.

For the record (and in my personal opinion) I'd put the top talk as
probably the one done by a reporter/author/risk communication expert (David
Ropeik) who is not an expert in our field at all but gave a fantastic talk
about how having all the competing rad units covering so many different
aspects makes it so that even journalists who want to be responsible and
accurate and thorough have a tough time if they haven't taken college
classes specifically with regards to radiation and how it is *OUR
COMMUNITY'S* responsibility to get out there and start clearing things up,
starting with those who do the communicating and the informing of the
biggest portions of the population.

On Mon, Mar 6, 2017 at 12:19 PM, Ted de Castro <tdc at xrayted.com> wrote:

> I have yet to see an cabinet x-ray leakage limit correctly specified in a
> MEASURABLE 35.8 pico C/Kg.sec - to go COMPLETELY SI (I hope I got that
> right).
>
> Haven't seen an IC survey meter yet scaled in pico C/Kg.sec either.  Are
> they sold that way in Europe??
>
> They all say mSv now - and that is incorrect.
>
> On 3/6/2017 9:10 AM, Jason Meade wrote:
>
>> "Did the workshop have anything to say about the rampant misuse of units
>> afforded us by SI?"
>>
>> Sort of, briefly, and quite indirectly.
>>
>> But it was more covered under the confusion and misdirection in
>> journalism,
>> in the public arena, and in emergency response communication issues due to
>> mix and match problems of dual system usage, an not really covered as a
>> separate issue.
>>
>> On Mon, Mar 6, 2017 at 11:53 AM, Ted de Castro <tdc at xrayted.com> wrote:
>>
>> Did the workshop have anything to say about the rampant misuse of units
>>> afforded us by SI?
>>>
>>> Thanks to an incredibly cumbersome EXPOSURE unit - regulatory exposure
>>> limits are now being expressed in DOSE units without specifying - dose to
>>> what.
>>>
>>> Back in the back old days when we where just too stupid to know any
>>> better
>>> these things were expressed in exposure units.  When a DOSE unit was
>>> expressed - rad - it was expressed as rad in xxxx. And was seldom
>>> measured
>>> but usually calculated.
>>>
>>> So I recently encountered a quasi regulatory document called SEMI 2 which
>>> has among other things:
>>>
>>> "Direct doserate measurement with an Ion Chamber {or equivalent)
>>> calibrated
>>> to +/- 10% of true doserate at the surface of the equipment (or at the
>>> closest
>>> approach) in all areas where the operator may have access with the
>>> ionizing
>>> radiation source active.*"
>>>
>>> *Sorry - wrong!  An ion chamber is an exposure instrument NOT dose rate -
>>> and this is for analytical x-ray for which the spectrum from one end to
>>> the
>>> other varies considerably and the exposure to dose ratio is spectrum
>>> dependent and will vary more than the requisite 10% from one end to the
>>> other.  Let along the body part to which their dose limits apply is not
>>> specified.  (they give the limits in Sv) I maintain there is in fact no
>>> survey instrument that can measure this!
>>>
>>> So - with their use of SI and misuse of type of unit we are confronted
>>> with a published imperative which is clearly impossible to comply with.
>>>
>>> So - what did the workshop have to say about ion chambers with Sv marked
>>> on the meter faces?
>>> *
>>>
>>> ***
>>> On 3/3/2017 5:51 AM, Jason Meade wrote:
>>>
>>> It was a great workshop and well worth my time, but after it was done,
>>>> I'm
>>>> pretty sure it will be done again with almost an identical agenda in 10
>>>> years time.
>>>>
>>>> Entirely too much "but this is the way we've always done it" and "it
>>>> would
>>>> be too hard" type talking among those who've always been doing the work
>>>> and
>>>> who are largely in charge for any type of shift in thinking, despite the
>>>> fact that the majority of the scientific and academic portions of our
>>>> education system have already made the change.
>>>>
>>>> On Thu, Mar 2, 2017 at 11:38 AM, Cary Renquist <cary.renquist at ezag.com>
>>>> wrote:
>>>>
>>>>   From the National Academies Press.
>>>>
>>>>> One can always download the PDF version for free (might require an
>>>>> account)
>>>>>
>>>>> Adopting the International System of Units for Radiation Measurements
>>>>> in
>>>>> the United States: Proceedings of a Workshop
>>>>>
>>>>> Most countries in the world use the SI (Système International, also
>>>>> known
>>>>> as the metric system) units for radiation measurements in commercial
>>>>> and
>>>>> technical activities. The United States, in contrast, uses a mix of SI
>>>>> and
>>>>> conventional units for radiation measurements, despite 30-year-old
>>>>> national
>>>>> and international recommendations to exclusively use SI. Radiation
>>>>> professionals in the United States are faced with the need to
>>>>> understand
>>>>> both systems and make conversions between the two.
>>>>> Short link
>>>>> http://bit.ly/2mPP5bQ
>>>>>
>>>>> Adopting the International System of Units for Radiation Measurements
>>>>> in
>>>>> the United States: Proceedings of a Workshop | The National Academies
>>>>> Press
>>>>> <https://www.nap.edu/catalog/24645/adopting-the-
>>>>> international-system-of-units-for-radiation-measurements-in-
>>>>> the-united-states?utm_source=NASEM+News+and+Publications&
>>>>> utm_campaign=b2788914c1-Final_Book_2017_03_02_24645&utm_
>>>>> medium=email&utm_term=0_96101de015-b2788914c1-102196093&
>>>>> goal=0_96101de015-
>>>>> b2788914c1-102196093&mc_cid=b2788914c1&mc_eid=3ee8f719d6>
>>>>>
>>>>>
>>>>> ---
>>>>> Cary Renquist
>>>>> cary.renquist at ezag.com
>>>>>
>>>>> _______________________________________________
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>>>>>
>>>>>
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>>
>>
>
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-- 
Thanks,
Jason A Meade, AS, BS, MHSA, RRPT, RT(T)
Senior Radiation Safety Specialist
Virginia Commonwealth University

Sanger Hall, B2-016
1101 East Marshall St
PO Box 980112
Richmond, VA 23298-0112

meadeja at vcu.edu

330-347-0271 cell
804-828-0594 office

"A society grows great
when old men plant trees
whose shade they know
they shall never sit in."
-Old Greek proverb

"You call this bad? I'll tell you what bad is....
Bad is passing test depth at 80 feet per second with a thirty degree down
bubble.
Compared to that, this is a walk in the park."
-Carlo Ciliberti