Model 3450
2–5
THIN LAYER
The Model 3450 contains two sets of G-M tubes for photon
detection. The set closest to the source rod is referred to as
System 1
,
while the set farthest from the source rod is
System 2
. When the
source rod is in the backscatter position, the source and the detectors
are on approximately the same plane.
Both System 1 and System 2 tube sets will primarily detect photons
that have been scattered by the material as described in the
theory of operation (see page 2–2). However, due to its greater
distance from the source, System 2 is more likely to detect scattered
photons from deeper in the material than is System 1. The
difference in the depth of material measured by each system, the
factory calibration, and mathematical modeling allow the 3450
gauge to determine the density of the top layer of material.
2. T
HEO
RY
OF
OP
ER
AT
ION
Summary of Contents for RoadReader Plus 3450
Page 7: ...Model 3450 vii NOTES...
Page 13: ...xii NOTES...
Page 17: ...1 4 GAUGE PARTS AND ACCESSORIES Figure 1 1 Model 3450 Parts and Accessories...
Page 23: ...2 4 Figure 2 1 Effect of Moisture on Depth of Measurement...
Page 53: ...3 28 NOTES...
Page 169: ...Appendix E 2 STANDARD COUNT LOG Gauge Serial Number Date Moisture MS Density DS1 Density DS2...
Page 171: ...Appendix E 4 STANDARD COUNT LOG Gauge Serial Number Date Moisture MS Density DS1 Density DS2...
Page 173: ...Appendix E 6 STANDARD COUNT LOG Gauge Serial Number Date Moisture MS Density DS1 Density DS2...
Page 175: ...Appendix E 8 STANDARD COUNT LOG Gauge Serial Number Date Moisture MS Density DS1 Density DS2...
Page 181: ...Appendix G 4 NOTES...
Page 187: ...Appendix H 6 NOTES...
Page 199: ...Index 12 NOTES...
