User manual

water from entering the case, and you also must prevent water
from condensing inside the RM-60. You could place it in a
sealed container along with a silica dehumidifying packet.
You can first dry the silica by placing it in an oven.
CIRCUIT DESCRIPTION
A regulated high voltage power supply draws minute power
from the computer and supplies the stainless steel Geiger-
Mueller tube with voltage. The Geiger-Mueller tube is filled
with a harmless inert gas and has a mica end window (alpha
window). When ionizing radiation enters the tube, the gas
ionizes, causing an avalanche of current. As the positive ions
migrate toward the cathode (stainless steel body) they are
quenched by a halogen quenching agent, otherwise they
would emit secondary electrons when striking the cathode,
causing a second avalanche.
SENSOR SPECIFICATIONS
Type 712 tube used in the RM-60
Window: Areal Density: 1.5 to 2.0 mg/cm
2
, Eff. Diameter:
0.360", Area: 0.102 Sq. In., Material: Mica
Wall: Thickness: 0.012", Eff. Length: 1.5", Eff. Diameter:
0.566", Material: 446 SS
Max. Diameter ................... 0.59 inches.
Max. length ................... 2.125 inches.
Dead time ................... 90 microseconds.
Alpha sensitivity ................... 2.5 Mev,
80% at 3.6 Mev.
Beta sensitivity ................... 35% at 50 Kev.
95% at 300 Kev.
Gamma & X-ray sensitivity ........ 10 Kev.
through end window, 40 Kev. through case.
Nominal cpm/mR/hr for Cs-137: 1050
The RM-60/RM-70 and software are digitally locked to the tube. Each tube
has passed all examinations, inspections, tests and calibrations of the LND
Quality Assurance Procedures including DCAS MIL-Q985A, MIL-E-I and
appendix B of 10CFR50. Calibration is accomplished in accordance with
MIL-STD-45662. Sources for calibration and/or dose rates have calibration
traceable to National Bureau of Standards.
The open area of the RM-60’s stainless steel mesh is 72%.
The tube is constructed of stainless steel, ceramic and mica.
It is fused shut with molten glass by heating in a furnace.
(See response graphs at end of manual).
LIMITED WARRANTY
Aware Electronics warrants the RM-60 to be free of defects
in material and workmanship for a period of five years from
the date of purchase provided the RM-60 has been handled
with care (as one would handle a camera). (Note: The geiger-
mueller tube sensor is warranted separately by the manufactur-
er for a period of six months.)
The remedy for breach of this warranty shall be limited to
repair or replacement and shall not encompass any other
damages, including but not limited to loss of profit, health,
special, incidental, consequential, or other similar claims.
Aware Electronics Corp. specifically disclaims all other war-
ranties, expressed or implied, including but not limited to
implied warranties of merchantability and fitness for a particu-
lar purpose.
PLEASE NOTE: Exceptfor thegraphson thelastpage,theremainderof
themanualis includedfor thebenefitof laymenusersof theRM-60.
COMMON SOURCES OF RADIATION
In addition to building materials and rocks, other, more radio-
active sources commonly exist around the house. For exam-
ple:
LANTERN MANTLES:
Lantern mantles from Army-Navy stores with Made in India
on the bag, are made from silk impregnated with thorium
salts. Thorium, a naturally occurring radioactive element,
primarily emits alpha particles, although many of its daughter
products emit high energy beta particles and gamma rays. It
is a dangerous material and we suggest that you handle lant-
ern mantles very carefully, particularly the ash, disposing of
it in a manner that will prevent inhalation by you and others.
SMOKE DETECTORS:
Many smoke detectors contain Americium 241 in their sens-
ing chambers. Americium 241 is a highly radioactive alpha
emitter, normally made in nuclear reactors by bombarding
plutonium with neutrons. Although smoke detectors are
useful devices, Americium 241 is extremely dangerous.
Therefore, do not dig out, prod, or otherwise disturb the
ionizing chamber of a smoke detector.
CLOCKS AND WATCHES:
Old radium watch faces have numbers and hands painted with
a radium salt/fluorescent mixture. Radium, and its daughter
products are vigorous alpha, beta and gamma emitters. The
alpha radiation from the radium causes the fluorescent materi-
al to glow-in-the-dark. This should not be confused with
glow in the dark fluorescent mixtures that are activated after
exposure to light. Radium watch faces are no longer manu-
factured. Although the quantity of radium in the paint is
extremely small, radium, and its daughter products, are ex-
tremely dangerous, therefore handle any old radium watches
with extreme care.
Newer, glow-in-the-dark watches, use tritium as a source of
radiation. Tritium is a byproduct of nuclear reactors, pro-
duced when the hydrogen in the reactor’s cooling water is
bombarded by neutrons. Tritium has several industrial and
military uses. It is a weak beta emitter, barely detectable with
the RM-60. The weak beta particles cannot penetrate the face
of the timepiece.
STATIC ELIMINATORS:
Some static eliminators, used to dissipate static electricity on
plastic films and records, contain small amounts of radioactive
polonium, a highly dangerous and vigorous alpha emitter.
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