[R-390] Re: Refinishing meters

Wed, 30 Apr 2003 14:57:09 -0700 (PDT)

From an old submariner:

Alpha isn't too bad.
Beta a little worse.
Gamma even worse.
Neutron, call the relatives and say goodbye

Characteristics of Alpha Radiation

1. Alpha radiation is not able to penetrate skin.

2. Alpha-emitting materials can be harmful to humans if the materials are inhaled, swallowed, or absorbed through open wounds. 

3. A variety of instruments have been designed to measure alpha radiation. Special training in use of these instruments is essential for making accurate measurements.

4. A civil defense instrument (CD V-700) cannot detect the presence of radioactive materials that produce alpha radiation unless the radioactive materials also produce beta and/or gamma radiation.

5. Instruments cannot detect alpha radiation through even a thin layer of water, blood, dust, paper, or other material, because alpha radiation is not penetrating.

6. Alpha radiation travels a very short distance through air.

7. Alpha radiation is not able to penetrate turnout gear, clothing, or a cover on a probe. Turnout gear and dry clothing can keep alpha emitters off of the skin.

Characteristics of Beta Radiation

1. Beta radiation may travel meters in air and is moderately penetrating.

2. Beta radiation can penetrate human skin to the "germinal layer," where new skin cells are produced. If beta-emitting contaminants are allowed to remain on the skin for a prolonged period of time, they may cause skin injury. 

3. Beta-emitting contaminants may be harmful if deposited internally.

4. Most beta emitters can be detected with a survey instrument (such as a CD V-700, provided the metal probe cover is open). Some beta emitters, however, produce very low energy, poorly penetrating radiation that may be difficult or impossible to detect. Examples of these are carbon-14, tritium, and sulfur-35.

5. Beta radiation cannot be detected with an ionization chamber such as a CD V-715.

6. Clothing and turnout gear provide some protection against most beta radiation. Turnout gear and dry clothing can keep beta emitters off of the skin.

Characteristics of Gamma Radiation and X-Rays

1. Gamma radiation and X-rays are electromagnetic radiation like visible light, radio waves, and ultraviolet light. These electromagnetic radiations differ only in the amount of energy they have. Gamma rays and X-rays are the most energetic of these.

2. Gamma radiation is able to travel many meters in air and many centimeters in human tissue. It readily penetrates most materials and is sometimes called "penetrating radiation."

3. X-rays are like gamma rays. They, too, are penetrating radiation.

4. Radioactive materials that emit gamma radiation and X-rays constitute both an external and internal hazard to humans.

5. Dense materials are needed for shielding from gamma radiation. Clothing and turnout gear provide little shielding from penetrating radiation but will prevent contamination of the skin by radioactive materials. 

6. Gamma radiation is detected with survey instruments, including civil defense instruments. Low levels can be measured with a standard Geiger counter, such as the CD V-700. High levels can be measured with an ionization chamber, such as a CD V-715.

7. Gamma radiation or X-rays frequently accompany the emission of alpha and beta radiation.

8. Instruments designed solely for alpha detection (such as an alpha scintillation counter) will not detect gamma radiation.

9. Pocket chamber (pencil) dosimeters, film badges, thermoluminescent, and other types of dosimeters can be used to measure accumulated exposure to gamma radiation.

-------Original Message-------
From: "[email protected]" <[email protected]>
Sent: 04/30/03 11:34 AM
To: "Scott, Barry (Clyde B)" <[email protected]>
Subject: Re: [R-390] Re: Refinishing meters

> 
> Simple folks.

IF the meter is an ORIGINAL, it's markings are RADIUM.  Radium may NOT 
still glow, BUT, it has a half-life in the OVER a thousand year range. 
 One of Radium's by products is Radon gas.

BOTH are Alpha emitters.  An alpha particle is the easiest to stop, BUT 
- is also the one that does the MOST damage.  Why else do you think that 
all the R-390As sold by Fair Radio only can be bought either with 
replacement meters or without meters at all?  The government was 
REQUIRED to dispose of them as Radioactive Waste.

A very good friend of mine, KA4SFV, is now a silent key.  He was exposed 
to Alpha particles thanks to nuclear testing.  The effects take a LONG 
TIME to get you, unless you get a very healthy dose.  I am NOT opening 
any original meters.

If someone has a GM counter - like an Eberline 500, if you get the 
chance, AND want to take a chance, remove the cover from the front of a 
meter - open the window on the bottom of the GM counter and PLEASE send 
us the resulting readout.

Bob - N0DGN

Scott, Barry (Clyde B) wrote:

>Roy,
>
>Good [repeat] advice.  One of the meters (Carrier Level) is marked
"Sealed -
>Do Not Open" while the other (Line Level) is not marked as such.  I
wonder
>if the Line Level meter would be considered "safe"?  I haven't opened
either
>of them, partly because of the radiation thing.  I have noticed that the
>Line Level meter doesn't appear to be all that well sealed (see pictures) 
so
>I'm thinking it may not be a threat.
>
>What think ye?
>
>73,
>
>Barry(III) - N4BUQ
>
>-----Original Message-----
>From: Roy Morgan [mailto:[email protected]]
>Sent: Wednesday, April 30, 2003 1:13 PM
>To: [email protected]
>Subject: Re: [R-390] Re: Refinishing meters
>
>
>At 07:01 PM 4/29/03 -0700, Ron wrote:
>  
>
>>David-
>>make yourself a wrench ... movement can be removed after removing the
nuts
>>on the back holding solder lugs.
>>    
>>
>
>Would-be Meter Disassembles,
>
>I have the urge to repeat Morgan's Law of Radioactive Meters and
Regulator 
>Tubes: tu wit:
>
>DON'T BREAK THEM OPEN AND EAT THE INSIDES.
>
>To elaborate slightly:
>
>1) SOME meters from R-390's and other radios have glow-in-the-dark meters 

>containing alpha-emitting radioactive sources.  (EVen though it does not 
>glow anymore, the stuff is still in there.)
>
>2) Many military OA2 and similar regulator tubes have small amounts of 
>radioactive material in them to ensure reliable ignition especially in
the 
>dark and cold.
>
>In both cases (pun intended!) the stuff is pretty harmless unless you get 

>the case open and get the material on you or inside you (by breathing or 
>ingestion or through a cut or abrasion).  Make sure this does not happen!
>
>What does "pretty harmless" mean? I remember one analysis that concluded 
>something like: You would have to place an R-390A meter on your chest or 
>cheek for about 34 years before you'd be exposed to radiation equivalent
to 
>the minimum yearly radiation exposure.  However, ingestion or inhaling
the 
>dust from a meter's markings or tube innards places the material in
direct 
>contact with your tissues and could lead eventually to cancer or the 
>like.  A sealed meter or unbroken regulator tube envelope effectively 
>contains all alpha emissions.
>
>The bottom line:
>
>If you are going to take R-390 meters apart:
>Make VERY sure you know what kind of meter you have and what you are
doing.
>
>Roy
>
>- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
>7130 Panorama Drive, Derwood MD 20855
>Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
>[email protected] --
>
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>  
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