Next Article in Journal
Myocardium Detection by Deep SSAE Feature and Within-Class Neighborhood Preserved Support Vector Classifier and Regressor
Next Article in Special Issue
Complete Meniscus Removal Method for Broadband Liquid Characterization in a Semi-Open Coaxial Test Cell
Previous Article in Journal
A Method for Simultaneously Measuring 6DOF Geometric Motion Errors of Linear and Rotary Axes Using Lasers
Previous Article in Special Issue
A Seven-Rod Dielectric Sensor for Determination of Soil Moisture in Well-Defined Sample Volumes
Open AccessArticle

Combined Thickness and Permittivity Measurement of Thin Layers with Open-Ended Coaxial Probes

1
NORCE Norwegian Research Centre AS, Fantoftvegen 38, NO-5892 Bergen, Norway
2
Department of Physics and Technology, University of Bergen, Allégaten 55, NO-5007 Bergen, Norway
*
Author to whom correspondence should be addressed.
This manuscript is extension version of the conference paper: Combined Thickness and Permittivity Measurement of Thin Layers with Open-Ended Coaxial Probes. In Proceedings of the 12th International Conference on Electromagnetic Wave Interaction with Water and Moist Substances (ISEMA), Lublin, Poland, 4–7 June 2018.
Sensors 2019, 19(8), 1765; https://doi.org/10.3390/s19081765
Received: 25 February 2019 / Revised: 9 April 2019 / Accepted: 11 April 2019 / Published: 12 April 2019
(This article belongs to the Special Issue Selected Papers from ISEMA 2018)
This paper presents a method to simultaneously determine the thickness and permittivity of thin layers from multi-frequency reflection coefficient measurements using an open-ended coaxial probe. This is achieved by exploiting that the probe becomes radiating at frequencies higher than the probe’s typical operating range. Permittivity information is extracted from measurements in the typical frequency range, whereas thickness information is obtained from high frequency measurements by exploiting resonances that occur when the radiated waves are reflected at the layer boundary. A finite element model of the measurement set-up is made in COMSOL MultiphysicsTM, and a matrix of simulations spanning the relevant layer thicknesses and permittivity range is generated. The measured permittivity spectra of unknown samples are compared to the simulation matrix to estimate layer thickness and permittivity. The method is verified by measurements of water–ethanol mixtures. An application example where the water fraction and layer thickness of a gas hydrate deposition layer is estimated from permittivity measurements in a multiphase flow loop is also presented. View Full-Text
Keywords: open-ended coaxial probe; permittivity; thickness measurement; finite element method open-ended coaxial probe; permittivity; thickness measurement; finite element method
Show Figures

Figure 1

MDPI and ACS Style

Folgerø, K.; Haukalid, K.; Kocbach, J.; Peterson, A.S. Combined Thickness and Permittivity Measurement of Thin Layers with Open-Ended Coaxial Probes. Sensors 2019, 19, 1765.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop