TY  - JOUR
AU  - Mester, A.
AU  - Zimmermann, Egon
AU  - Van der Kruk, J.
AU  - Vereecken, H.
AU  - Van Waasen, S.
TI  - Development and drift-analysis of a modular electromagnetic induction system for shallow ground conductivity measurements
JO  - Measurement science and technology
VL  - 25
IS  - 5
SN  - 1361-6501
CY  - Bristol
PB  - IOP Publ.
M1  - FZJ-2014-02814
SP  - 055801
PY  - 2014
AB  - Electromagnetic induction (EMI) is used for fast near surface mapping of the electrical conductivity (EC) for a wide range of geophysical applications. Recently, enhanced methods were developed to measure depth-dependent EC by inverting quantitative multi-configuration EMI data, which increases the demand for a suitable multi-channel EMI measurement system. We have designed a novel EMI system that enables the use of modular transmitter/receiver (TX/RX) units, which are connected to a central measurement system and are optimized for flexible setups with coil separations of up to 1.0 m. Each TX/RX-unit contains a coil, which is specifically adjusted for transmitting or receiving magnetic fields. All units enable impedance measurements at the coils, which are used to simulate its electrical circuit and analyze temperature-induced drift effects. A laboratory drift analysis at 8 kHz showed that 88% of the drift in the measured data is due to the change in the electrical transmitter coil resistance. The remaining 12% is due to changes in the transmitter coil inductance and capacitance, the receiver impedance and drifts in the amplification circuit. A measurement under field conditions proved that the new EMI system is able to detect a water-filled swimming pool with 50 mS m−1, using a coil separation of 0.3 m. In addition, the system allows in-field ambient noise spectra measurements in order to select optimal low-noise measurement frequencies
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000334352000041
DO  - DOI:10.1088/0957-0233/25/5/055801
UR  - https://juser.fz-juelich.de/record/153151
ER  -