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Question on MicroRems VS MilliRems & CDV-700
StAnDaRdS don't ya love them?
More below but short answer is milli Roentgens per Hour. This applies only
to readings of Gammas, not mixed Gamma and Beta. In other words shield must
be closed. Otherwise use the CPM ( counts per minute) scale.
Mid scale would be .25 times the range setting , so say .25 x 10= 2.5
milliRoentgens per Hour. On the X1 scale, it is read direct or .25 (
one-quarter) mR/H. On the X100 it is 25 mR/H.
-----
From: "jmarkitell" <jmarkitell@...>
> Hi Folks,
>
> Please pardon the simple nature of this question, but are the
> CDV-700 scales expressed in Microrems or Millirems? Can someone give
> an example of both of their abbreviations? I was never sure if MhR is
> milli or micro and a batch of hot rocks I'm looking at read 300
> microrems....one would read midscale on the CDV-700 on the 10x
> setting, the other would be way off scale (provided the meter measures
> microrems). Thanks in advance!
>
> Jim Markitell
NOT a simple question, there is a LOT of confusion over this topic, and some
of it is perpetuated by mistakes.
Micro means one-millionth and is represented by the Greek letter MU but we
don't have Greek keyboards so we often use the small letter U instead= uR,
for microRoentgens
Milli means one-thousandth ( 1/1000 or "10 to minus 3" or (10E-3) and is the
small letter m. CDV 700 is milli-Roentgens per Hour.
Mega means one million ( x 1,000,000) and is the capital M.
R is the symbol for Rankine ( WHAT?, yes it's true, or at least it was).
r is ( was) the symbol for Roentgen
Nowadays Hertz has replaced cycles, MegaHertz replaces Mc, and R is
Roentgen, and Rankine is lost in the shuffle. Rankine was a temperature
scale like Kelvin, but used Fahrenheit degrees instead of Celsius ( or is it
Centigrade still?).
Clear on this>"!"?
But I digress.
A special Standard trefoil symbol was invented to indicate the presence of
radiation, sort of a short cut, but no one knew what to call it, so it's
name is" Radiation Warning Symbol". Seems like it should have a better name
than that. After a person. How about the Geo? Nah.
Back to Rads and Roentgens:
Roentgens are a unit of exposure to Gamma or X-Rays. ( used in Dosimeters)
R/Hr is a rate of exposure RATE measurement unit ( used in survey meters)
Rads are the unit of dose that supercedes the Roentgen,
REM is the dose in humans or "Roentgen Equivalent Man" not to be confused by
the REP or "Roentgen Equivalent Physical".
Curie is the activity level of a nuclide and is a description of the number
of decays per second, now replaced by the Bq.
Absorbed dose, once Rad are now Gray, and that makes me Blue.
And not to forget the REM is now Sievert.
Thank you George Orwell for introducing NEWSPEAK.
Have Fun ( used to be called Be Gay)
Geo
More below but short answer is milli Roentgens per Hour. This applies only
to readings of Gammas, not mixed Gamma and Beta. In other words shield must
be closed. Otherwise use the CPM ( counts per minute) scale.
Mid scale would be .25 times the range setting , so say .25 x 10= 2.5
milliRoentgens per Hour. On the X1 scale, it is read direct or .25 (
one-quarter) mR/H. On the X100 it is 25 mR/H.
-----
From: "jmarkitell" <jmarkitell@...>
> Hi Folks,
>
> Please pardon the simple nature of this question, but are the
> CDV-700 scales expressed in Microrems or Millirems? Can someone give
> an example of both of their abbreviations? I was never sure if MhR is
> milli or micro and a batch of hot rocks I'm looking at read 300
> microrems....one would read midscale on the CDV-700 on the 10x
> setting, the other would be way off scale (provided the meter measures
> microrems). Thanks in advance!
>
> Jim Markitell
NOT a simple question, there is a LOT of confusion over this topic, and some
of it is perpetuated by mistakes.
Micro means one-millionth and is represented by the Greek letter MU but we
don't have Greek keyboards so we often use the small letter U instead= uR,
for microRoentgens
Milli means one-thousandth ( 1/1000 or "10 to minus 3" or (10E-3) and is the
small letter m. CDV 700 is milli-Roentgens per Hour.
Mega means one million ( x 1,000,000) and is the capital M.
R is the symbol for Rankine ( WHAT?, yes it's true, or at least it was).
r is ( was) the symbol for Roentgen
Nowadays Hertz has replaced cycles, MegaHertz replaces Mc, and R is
Roentgen, and Rankine is lost in the shuffle. Rankine was a temperature
scale like Kelvin, but used Fahrenheit degrees instead of Celsius ( or is it
Centigrade still?).
Clear on this>"!"?
But I digress.
A special Standard trefoil symbol was invented to indicate the presence of
radiation, sort of a short cut, but no one knew what to call it, so it's
name is" Radiation Warning Symbol". Seems like it should have a better name
than that. After a person. How about the Geo? Nah.
Back to Rads and Roentgens:
Roentgens are a unit of exposure to Gamma or X-Rays. ( used in Dosimeters)
R/Hr is a rate of exposure RATE measurement unit ( used in survey meters)
Rads are the unit of dose that supercedes the Roentgen,
REM is the dose in humans or "Roentgen Equivalent Man" not to be confused by
the REP or "Roentgen Equivalent Physical".
Curie is the activity level of a nuclide and is a description of the number
of decays per second, now replaced by the Bq.
Absorbed dose, once Rad are now Gray, and that makes me Blue.
And not to forget the REM is now Sievert.
Thank you George Orwell for introducing NEWSPEAK.
Have Fun ( used to be called Be Gay)
Geo
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