11
Figure 4:
Comparison of neutron probe, TRIME-T3 and gravimetric method for water content
determinations in a loess soil.
Figure 5 :
Comparison of neutron probe and TRIME-T3 for water content determinations an illitic clay.
Some materials, especially very clayey soils and soils with high organic contents, can afford material
specific calibrations due to their different dielectric behaviour.
A limiting factor in TDR measuring is the bulk soil electrical conductivity. For the TRIME-T3 tube probe,
bulk soil electrical conductivity should not exceed 1 dS/m. Note that bulk soil electrical conductivity is a
combination of the pore water electrical conductivity and the surface conductivity of the soil matrix. Due
to the tortuous nature of the conductivity path in the soil (soil type dependent), the bulk soil conductivity
is much lower than the electrical conductivity of the pore water and it is dependent on water content.
2.4 Summary
The TRIME tube probe is a promising new tool for determining water content profiles with the TDR
method. Fast, routine and non destructive measurements of water content without the use of
hazardous radioactive materials are possible. A measuring accuracy of
±
2 vol.-% is possible, provided
that soil and access tube are in close contact and bulk soil electrical conductivity doesn’t exceed
1 dS/m.
Summary of Contents for TRIME-FM
Page 1: ...TRIME FM User Manual ...
