BERTHOLD TECHNOLOGIES Uni-Probe LB 490, Руководство пользователя

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6 Radiation Protection Volume 1
Distance
This means the distance between the radioactive source and the
human body. The radiation intensity (dose rate) decreases - like
light - in proportion to the square of the distance; this means, dou-
bling the distance to the source will reduce the dose rate to one
quarter.
Conclusion:
When handling radioactive substances, maximum distance to the
source should be maintained. This is especially true for persons
that are not directly involved in this work.
Time
The total time a person stays in the vicinity of a radiometric mea-
suring system and the body is exposed to radiation. The effect is
cumulative and increases therefore with the duration of the radia-
tion exposure.
Conclusion:
Any work in the vicinity of radiometric measuring system must be
prepared carefully and organized such that it can be carried out in
the shortest time possible. Having the proper tools is of particular
importance.
Shielding
The material surrounding the source provides the shielding effect.
As the shielding effect depends, following an exponential function,
on the product of thickness multiplied by the density, it follows that
material with a high specific weight are used for shielding pur-
poses. The device designer usually calculates suitable dimensions.
Conclusion:
Before mounting or dismounting the shielding, make sure that the
radiation exit channel is
locked in the closed position.