Appendix A–6
LIMITING EXPOSURE
Under average conditions, an individual working with the 3451
gauge will receive less than 200 millirem per year.
A basic principle of radiation protection is that radiation exposure
should be kept as far below the limits as is reasonably achievable.
This is known as the
ALARA
(as low as reasonable achievable)
principle. The three methods for limiting exposure are:
Time
Distance
Shielding
Time
The simplest way to reduce exposure is to minimize the time spent
around a radioactive source. If the time spent near a source is cut in
half, then the exposure is halved, 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 A–2). Doubling the distance from
a radiation source reduces the exposure to one-fourth its original
value. If the distance is tripled, then the exposure is reduced by a
factor of nine, and so on.
Содержание Enhanced RoadReader Plus 3451
Страница 7: ...Model 3451 vii NOTES...
Страница 17: ...xvi NOTES...
Страница 29: ...1 12 NOTES...
Страница 33: ...2 4 Figure 2 1 Effect of Moisture on Depth of Measurement...
Страница 85: ...4 22 NOTES...
Страница 106: ...Model 3451 6 3 Figure 6 1 Offset Menu 6 OFFSETS CALIBRATION...
Страница 114: ...Model 3451 6 11 Figure 6 10 Moisture Offset Erase Prompt 6 OFFSETS CALIBRATION...
Страница 127: ...6 Figure 6 25 Enter File Name Figure 6 23 Input True Density Figure 6 24 Thin Layer Special Calibration Results...
Страница 131: ...6 NOTES...
Страница 141: ...7 10 Figure 7 5 Project Data Spreadsheet...
Страница 145: ...7 14 Figure 7 8 Project Setup Display Figure 7 9 Standard Counts Display...
Страница 147: ...7 16 Figure 7 10 Project Status Display Figure 7 11 Source Decay Display...
Страница 149: ...7 18 Figure 7 12 Stat Test Display Figure 7 13 Drift Test Display...
Страница 153: ...7 22 NOTES...
Страница 166: ...Model 3451 Appendix A 13 Figure A 3 Cleaning the Sliding and Fixed Blocks...
Страница 174: ...Model 3451 Appendix A 21 NOTES...
Страница 175: ......
Страница 183: ...Appendix B 8 NOTES...
Страница 187: ...Figure C 5 Review Stat Test Appendix C 4 Figure C 3 View Stat Counts Figure C 4 Stat Test Results...
Страница 221: ...Appendix D 6 NOTES...
Страница 223: ...Appendix E 2 STANDARD COUNT LOG Gauge Serial Number Date Moisture MS Density DS1 Density DS2...
Страница 225: ...Appendix E 4 STANDARD COUNT LOG Gauge Serial Number Date Moisture MS Density DS1 Density DS2...
Страница 227: ...Appendix E 6 STANDARD COUNT LOG Gauge Serial Number Date Moisture MS Density DS1 Density DS2...
Страница 229: ...Appendix E 8 STANDARD COUNT LOG Gauge Serial Number Date Moisture MS Density DS1 Density DS2...
Страница 235: ...Appendix G 4 NOTES...
Страница 246: ...Model 3451 Warranty 1 NOTES WARRANTY...
