TY  - JOUR
A1  - Chen, Zhen
A1  - Schwing, Moritz
A1  - Karlovšek, Jurij
A1  - Wagner, Norman
A1  - Scheuermann, Alexander
T1  - Broadband Dielectric Measurement Methods for Soft Geomaterials: Coaxial Transmission Line Cell and Open-Ended Coaxial Probe
JF  - International Journal of Engineering and Technology
N2  - Broadband dielectric measurement methods based on vector network analyzer coupled with coaxial transmission line cell (CC) and open-ended coaxial probe (OC) are simply reviewed, by which the dielectric behaviors in the frequency range of 1 MHz to 3 GHz of two practical geomaterials are investigated. Kaolin after modified compaction with different water contents is measured by using CC. The results are consistent with previous study on standardized compacted kaolin and suggest that the dielectric properties at frequencies below 100 MHz are not only a function of water content but also functions of other soil state parameters including dry density. The hydration process of a commercial grout is monitored in real time by using OC. It is found that the time dependent dielectric properties can accurately reveal the different stages of the hydration process. These measurement results demonstrate the practicability of the introduced methods in determining dielectric properties of soft geomaterials.
KW  - Impedanzspektroskopie
KW  - Electromagnetic properties of porous materials
KW  - Koaxialkabel
KW  - Dielectric spectroscopy
KW  - open-ended coaxial probe
KW  - coaxial transmission line
KW  - real-time monitoring
KW  - physicochemical properties of geomaterials
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20210408-43984
UR  - http://www.ijetch.org/index.php?m=content&c=index&a=show&catid=58&id=838
VL  - 2014
IS  - volume 6, number 5
SP  - 373
EP  - 380
ER  - 
TY  - JOUR
A1  - Scheuermann, Alexander
A1  - Huebner, Christof
A1  - Schlaeger, Stefan
A1  - Wagner, Norman
A1  - Becker, Rolf
A1  - Bieberstein, Andreas
T1  - Spatial time domain reflectometry and its application for the measurement of water content distributions along flat ribbon cables in a full-scale levee model
JF  - Water Resources Research
N2  - Spatial time domain reflectometry (spatial TDR) is a new measurement method for determining water content profiles along elongated probes (transmission lines). The method is based on the inverse modeling of TDR reflectograms using an optimization algorithm. By means of using flat ribbon cables it is possible to take two independent TDRmeasurements from both ends of the probe, which are used to improve the spatial information content of the optimization results and to consider effects caused by electrical conductivity. The method has been used for monitoring water content distributions on a full-scale levee model made of well-graded clean sand. Flood simulation tests, irrigation tests, and long-term observations were carried out on the model. The results show that spatial TDR is able to determine water content distributions with an accuracy of the spatial resolution of about ±3 cm compared to pore pressure measurements and an average deviation of ±2 vol % compared to measurements made using another independent TDR measurement system.
KW  - Damm
KW  - Infiltration
KW  - Bodenfeuchte
KW  - Transient and time domain; Dams; Infiltration; Soil moisture; calibration; levee model; soil moisture measurement; spatial time domain reflectometry
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20170425-31601
ER  -