Model 3400-B Series
LIMITING EXPOSURE
Current regulations for both NRC and Agreement States have
established a whole body occupational exposure limit of 5,000
millirem per year. Under normal conditions a full time operator
of a 3400 series will receive less than 200 millirem per year.
Taking advantage of all available means to limit radiation
exposure is always recommended. The three methods of
limiting exposure are:
Time
Distance
Shielding
These methods are a part of an "
ALARA
" (
A
s
L
ow
A
s
R
easonably
A
chievable) program.
TIME
The simplest way to reduce exposure is to keep the time spent
around a radioactive source to a minimum. If time is cut in half,
so is the exposure, with all other factors remaining constant.
DISTANCE
Distance is another effective means to reduce radiation
exposure. A formula known as the "inverse square law" relates
the radiation exposure rate to distance (Figure 15). Doubling
the distance from a radiation source reduces the exposure to
one-fourth its original value. If the distance is tripled, the
exposure is reduced by a factor of nine, etc.
Содержание 3411-B
Страница 3: ...Model 3400 B Series iii...
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Страница 15: ...Model 3400 B Series 1 3 Figure 1 Gauge and Accessories...
Страница 20: ...2 4 Figure 2 3411 B Front Panel Controls...
Страница 30: ...3 8 NOTES...
Страница 44: ...5 8 Figure 4 Roller Pattern...
Страница 56: ...6 6 The following is an example of the stat test and drift test Figure 9 Statistical Stability Test...
Страница 76: ...Appendix A 16 NOTES...
Страница 91: ...Model 3400 B Series Appendix C 3 Figure 15 Direct Transmission and Backscatter Geometries...
Страница 92: ...Appendix C 4 Figure 16 Backscatter Surface Density Effects...
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Страница 105: ...Model 3400 B Series Appendix E 1 A Ap pp pe en nd di ix x E E S St ta an nd da ar rd d C Co ou un nt t L Lo og g...
Страница 106: ...Appendix E 2 STANDARD COUNT LOG Serial Number Date Moisture MS Density DS Date Moisture MS Density DS...
Страница 108: ...Appendix E 4 NOTES...
