LB 379
24
Natural radiation exposure
For comparison
’
s sake, it may be helpful to look at the average radiation exposure for the
population in Germany. It is approx. 4000
Sv (400 mrem) per year. In addition, there is
the medical radiation exposure, caused by X-rays, etc., which is about 500
Sv (50 mrem),
and radiation exposure caused by other sources of about 100
Sv (10 mrem). Particularly
the natural radiation exposure may vary significantly, depending on location, and may
sometimes be more than 10 times above the value specified above.
Protective measures
The following protective measures will help reduce the radiation exposure of persons han-
dling radioactive substances to a fairly low radiation dose:
1. Shielding
Radioactive sources are usually delivered in a shielded container with lockable beam
exit channel. DO NOT OPEN THIS BEAM EXIT CHANNEL BEFORE ASSEMBLY IS FULLY
COMPLETED. The nuclide, the activity, the shielding thickness and the dose rate at
a certain distance are indicated on the type plate. Based on these figures, the dose
accumulated while working with the radioactive sources is calculated or at least
estimated. To get more accurate results, we recommend using a dosimeter.
2. Time
As the formula for the calculation of the absorbed dose shows, the dose is the
greater the longer one is exposed to radiation. Therefore, it is especially important
when working with radioactive sources to prepare work carefully and complete it
quickly. This is especially true when the shielding thickness had to be kept low for
technical reasons, or if one has to work with an unshielded source - which must be
avoided as far as possible.
3. Distance
Doubling the distance between the body and the radioactive source reduces the
intensity of radiation to a quarter. This fact is especially important if you have to
work with an unshielded source. In this case, the source of radiation should never
be touched with the hands, because then the distance from the radiation source is
almost 0. By using a pair of pliers, you can increase the distance from the radiation
source to your hand from 1 to 20 cm; this means a reduction of the dose rate by a
factor of 400!
Summary
If a radiometric measuring system is used as intended, the dose rate is so low that it
usually lies below the detection limit of dosimeters. Even if one has to work with an un-
shielded source for a short time, the radiation dose can be limited through good preparation
of the work and by keeping a fairly large distance between body and source, so that the
body is exposed to a dose that is only a fraction of the natural radiation exposure. Never-
theless, one should heed the legislator's requirement:
THE RADIATION EXPOSURE WHEN HANDLING RADIOACTIVE MATERIALS MUST BE KEPT
AS LOW AS POSSIBLE.
Summary of Contents for LB 3602
Page 1: ...Measuring Path LB 379 and LB 3602 3603 Operating Manual 40437BA2 Rev No 00 12 2016...
Page 2: ...LB 379 2...
Page 4: ...LB 379 4...
Page 31: ...LB 379 31 9 Dimensional Drawings 9 1Measuring Path LB 379 with DIN Flange...
Page 32: ...LB 379 32 9 2Measuring Path LB 379 with ASA Flange...
Page 33: ...LB 379 33 9 3Measuring Path LB 379 with Threaded Connector...
Page 34: ...LB 379 34 9 4Measuring Path LB 3602 03...
Page 35: ...LB 379 35 10 ATEX Certificate...
Page 36: ...LB 379 36...
Page 37: ...LB 379 37...
Page 38: ...LB 379 38...
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