Model 3400-B Series
5-9
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Nuclear gauges, when used in the backscatter mode on overlays
less than 7 cm (3 in.), have certain limitations that must be
overcome in order to obtain correct densities. The problem
arises because the gauge “sees” through the thin overlay and
therefore the underlying material influences the reading.
Recognizing this problem, a nomograph was developed that
allows rapid determination of overlay density. To use the
nomograph, you must know the density of the bottom layer and
the thickness of the top layer.
The simplest method of determining the bottom layer density is
by taking nuclear density tests before the overlay is applied.
Pavement is then placed and compacted.
Backscatter density measurements are made on top of the new
pavement. Knowing the mat thickness, the density of the top
layer may be determined from the nomograph.
NOTE
These procedures and nomographs are applicable
only to the 3401-B and 3411-B gauges. They are not
valid for other Troxler gauges or gauges from other
manufacturers.
Following are examples with nomographs for SI and US
Customary Units.
Содержание 3411-B
Страница 3: ...Model 3400 B Series iii...
Страница 10: ......
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...
Страница 104: ......
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...
