Troxler 3411-B, Manual Of Operation And Instruction

Page: 40 / 109

5-4
The correction is independent of dry density and wet density
and adjusts the apparent moisture to true moisture regardless
of dry density. This value can be used for all future tests on the
same soil type.
NOTE
Occasionally, non-homogenous soils may be
encountered in which differences between oven dry
and gauge readings are not consistent. In this case,
one correction factor is not practical.
FOR THE 3401-B
Calculate the moisture from the oven dry in kg/m
3
or pcf:
M Oven Dry =
%M Oven Dry x WD
%M Oven Dry + 100
Here, WD = Wet Density
Next, calculate the correction factor in kg/m
3
or pcf:
Correction factor = M Oven Dry – M Gauge
This factor should be used to adjust the gauge moisture reading,
paying attention to the algebraic signs.
This correction factor is accurate at the wet density and percent
moisture taken. Therefore, the samples taken should be close to
optimum compaction. This value can be used on all future tests
on the same soil type.
M Oven Dry =
5.5 x 130
5.5 + 100
= 6.8
Correction Factor = 6.8 – 9.6 = -2.8 PCF