User manual

occurs in X-ray tubes and in high voltage tubes in some TV
power supplies. They are just like low energy gamma rays,
except that gamma rays originate from the nucleus of radio-
active atoms, whereas X-rays originate from interactions
involving orbital electrons.
To distinguish X-rays and low level gamma rays, hold the
back of the RM-60 toward the source. X-rays and low energy
gamma rays will not be able to penetrate the side of the stai-
nless steel geiger tube, with enough energy to produce a
detection.
Next point the alpha window towards the source. X-rays and
low energy gamma rays will penetrate the alpha window,
thereby producing a detection.
Next place a 1/16" piece of aluminum between the source and
alpha window. Unlike alpha particles or beta particles, X-rays
and low energy gamma rays will be able to penetrate the
aluminum, therefore a detection of radiation indicates X-rays
or low level gamma rays.
RADON and THORON GAS
THORON GAS:
Many building materials contain small quantities of thorium.
Thorium-232 is a radioactive element that heads a series of
radioactive elements, just as uranium-238 heads a series of
radioactive elements. Thorium is far more abundant in nature
than is scarce uranium. Thorium is almost as abundant as
lead.
Thorium decomposes into thoron gas, an isotope of radon.
Thoron gas has a halflife of only 55 seconds (half of a given
quantity of thoron decomposes into radioactive solids every
55 seconds). Because of the short halflife, most sub-surface
(underground) thoron gas decomposes into radioactive solids
before it has a chance to escape into the atmosphere or seep
into a house.
Thoron gas released from building materials can immediately
enter the living space atmosphere, without first having to seep
up through many feet of sub-surface soil.
When thoron gas decomposes in a living space atmosphere,
it releases solid charged radioactive products of decomposition
(daughter products). These daughter products cling to floating
dust particles, and if inhaled, can lodge in the body and
induce cancers.
The RM-60 can detect these dangerous radioactive daughter
products of thoron by measuring the buildup of radioactivity
on an air filter. An air filter will become radioactive as it
catches thoron daughter products clinging to dust particles.
(see RADON GAS);
RADON GAS:
PAST EXPERIENCE:
Over the years, many users of the RM-60 system have sent to
Aware, graphs and letters, showing the great value the system
provides for watching real time radon levels. Experience has
indicated one can expect an increase over and above normal
background reading of perhaps 3 micro roentgen per hour
per pico curie radon per liter air. In other words, if your
background reading outdoors or upstairs, where there is no
radon, is 10 microR/hr., but you measure a background
reading of 13 micro/R/hr. in the basement, this perhaps
indicates approx. 1 pico curie radon per liter air. A reading
of 16 micro/R/hr. would indicate 2 pico curies radon per liter
air, etc.
By placing the RM-60 window within perhaps 0.3 inch from
the filter of a small fan-filter combination, the increase in
readings due to the presence of radon will perhaps more than
double, that is approx. 7 microR/hr. increase per pico curie
radon per liter air. A buildup of radioactivity on an air filter
is a very strong indication of the presence of radon.
Some users have indicated a large buildup of radioactivity in
the bathroom, when running the shower. For example, one
user measured approx. 15 microR/hr. in the bathroom, but
after running the shower, the reading increased to approx.
200 microR/hr., as radon and daughters were released into
the air from the water.
As indicated above, with the help of an air filter, your RM-60
can detect very low levels of radon gas. This same test
procedure also will alert you to the presence of rare but highly
dangerous airborne radioactive particles.
QUICK RADON TEST:
Hold a coffee filter over the inlet of a vacuum cleaner for 2
mins., then place the filter on top of the RM window, or run
a fan forced air filter for 1/2 to one hour then pull the filter
out of the plenum, as though you were going to clean or
replace it, and place the RM-60 right on top of the filter. If
you have even the smallest buildup of radon gas in your
house, you should notice an increase in the reading. Also, see
DECAY CURVES. By performing this test several times a
year, you will be alerted to any buildup of radon.
Suitable filter systems include good quality filters in a heating
or air conditioning system, charcoal filters such as those
mounted above a stove, or portable filters. Sears sells a line
of inexpensive portable electrostatic filters.
RM-60 users who have contacted Aware Electronics and who
have an enclosure containing radon, such as a basement, have
noticed an increase in the background radiation level when
placing the RM-60 in the enclosure, without the use of an air
filter. By moving the RM-60 around from location to loca-
tion, they are able to ascertain likely areas of radon ingress.
Puffs or spurts of high activity are often observed in a partic-
ular location, for example next to a particular wall.
RM-60 users who have had radon remedy work, use the RM-
60 to check for the return of any radioactive build-up.
RADON DISCUSSION:
Radon gas is released by radium, found in association with
uranium, primarily in soil and rock. If radon decomposes in
the atmosphere, the radioactive daughter products cling to dust
particles.
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