Troxler 3430-M, Manual Of Operation And Instruction

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Model 3430 A-5
RADIATION SAFETY
This section provides a brief discussion of general radiation safety.
The exposure profile for the Model 3430 gauge is also included,
along with a discussion of the source encapsulation.
TYPES OF RADIATION
The radioactive sources in the Model 3430 produce four types of
radiation:
Alpha Particles
Beta Particles
Photons (Gamma Rays)
Neutrons
The alpha and beta particles are stopped by the source capsule. Only
the photons and neutrons contribute to any occupational radiation
exposure.
Photon (gamma) radiation is electromagnetic radiation, as are x-
rays, radio waves, and visible light. Photons have no mass, no
electrical charge, and travel at the speed of light. Photons are
energetic and penetrating. Dense materials (such as lead, tungsten,
and so on) provide the best shielding against photon radiation.
Neutron radiation allows measurement of the hydrogen (water)
content in a material because the neutrons are slowed by collisions
with materials containing hydrogen atoms (i.e. water, polyethylene,
etc). Neutrons have no charge and are very penetrating.
LIMITING EXPOSURE
Government agencies set occupational exposure limits. The current
limit in the United States and many other countries is 5,000 mrem
per year. Under average conditions, a full-time employee working
with the 3430 gauge will receive less than 200 mrem per year. By
comparison, people in the US receive an average of 360 mrem per
year from natural background radiation and medical radiation.
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