Model 3430 Plus & 3440 Plus
9–5
SOURCE DECAY
The strength of radioactive material is measured by its activity, or
rate of decay. This activity decreases with time. The length of time
it takes a given amount of radioactive material to decay to half of its
original strength is referred to as the
half-life
. The half-life of the
Am-241:Be source is 432 years. The half-life of the Cs-137 source
is 30 years.
The
Source Decay
function allows the operator to view how the
decrease in the radiation intensity of the source affects gauge
density measurements. It displays the actual density standard count,
the predicted standard count, and the percent difference between the
two sets of counts. The gauge calculates the predicted standard
count based upon the density standard count at the time the gauge
was calibrated and the number of days that have elapsed since
calibration.
To access the
Source Decay
function, press
〈
5
〉
at the
Extended
menu shown on page 9–1. The gauge displays:
To return to the
Extended
menu, press the
〈
ENTER/START
〉
or
〈
ESC
〉
key.
9. EXT
EN
DED
M
EN
U
Summary of Contents for 3430 Plus
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Page 7: ...Model 3430 Plus 3440 Plus vii NOTES ...
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Page 122: ...9 NOTES ...
Page 142: ...Appendix A 20 NOTES ...
Page 178: ...Appendix D 2 STANDARD COUNT LOG Gauge Serial Number Date MS DS Date MS DS ...
Page 180: ...Appendix D 4 STANDARD COUNT LOG Gauge Serial Number Date MS DS Date MS DS ...
Page 190: ...Appendix F 8 NOTES ...
Page 194: ...Appendix G 4 NOTES ...
Page 200: ...Appendix H 6 NOTES ...
Page 215: ...Model 3430 Plus 3440 Plus Index 11 W Wide Area Augmentation System WAAS 2 Y YES key 3 4 INDEX ...
Page 216: ...Index 12 NOTES ...
Page 217: ...Model 3430 Plus 3440 Plus Warranty 1 NOTES WARRANTY ...