Development of a Time-Domain Reflectometry System for Dielectric Properties Measurement

1985 ◽  
Vol 28 (4) ◽  
pp. 1313-1318 ◽  
Author(s):  
Wanda L. Bellamy ◽  
Stuart O. Nelson ◽  
Richard G. Leffler
Keyword(s):  
Dielectric Properties ◽  
Time Domain ◽  
Time Domain Reflectometry

scholarly journals A Time-Domain Reflectometry Method with Variable Needle Pulse Width for Measuring the Dielectric Properties of Materials

Sensors ◽  
2016 ◽  
Vol 16 (2) ◽  
pp. 191 ◽  
Author(s):  
Andrzej Wilczek ◽  
Agnieszka Szypłowska ◽  
Marcin Kafarski ◽  
Wojciech Skierucha
Keyword(s):  
Dielectric Properties ◽  
Time Domain ◽  
Pulse Width ◽  
Time Domain Reflectometry ◽  
Properties Of Materials

Frequency analysis of time‐domain reflectometry (TDR) with application to dielectric spectroscopy of soil constituents

Geophysics ◽  
1999 ◽  
Vol 64 (3) ◽  
pp. 707-718 ◽  
Author(s):  
Richard Friel ◽  
Dani Or
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Frequency Domain ◽  
Time Domain ◽  
Dominant Role ◽  
Primary Objective ◽  
Time Domain Reflectometry ◽  
Complete Picture ◽  
Frequency Dependent ◽  
Additional Information

Standard analyses of time‐domain reflectometry (TDR) waveforms in environmental sciences use traveltime along waveguides and reflection amplitude to infer water content and bulk electrical conductivity, respectively. TDR waveforms contain additional information on the frequency‐dependent dielectric permittivity of media, which can be extracted through transformation of TDR waveforms into the frequency domain. The primary objective of this study was to provide a more complete picture of TDR responses in the frequency domain and to improve estimation of dielectric properties. The frequency content of TDR waveforms interacting with various constituents was measured and compared with predictions based on known dielectric properties and waveguide geometries. The study highlights the dominant role of the S11 scatter function, which describes how a TDR signal is modified by media properties and probe configuration. Scatter functions derived from transformed TDR waveforms into the frequency domain were used for estimation of frequency‐dependent dielectric properties of wet soils. The main results were (1) a more complete picture of TDR waveforms in the frequency domain; (2) estimation and use of scatter functions for TDR‐based dielectric permittivity estimation; and (3) highlights of potential usefulness and limitations of a commonly used TDR cable tester (Tektronix 1502B) and waveguide design for estimation of frequency‐dependent dielectric properties of porous media.

scholarly journals Dielectric properties of benzylamine in 1,2,6-hexanetriol mixture using time domain reflectometry technique

2016 ◽  
Vol 06 (04) ◽  
pp. 1650034
Author(s):  
M. B. Swami ◽  
P. G. Hudge ◽  
V. P. Pawar
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Binary Mixtures ◽  
Time Domain ◽  
Complex Permittivity ◽  
Intramolecular Interaction ◽  
Correlation Factor ◽  
Time Domain Reflectometry ◽  
Least Square ◽  
Kirkwood Correlation Factor

The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry (TDR) technique in the frequency range of 10 MHz to 30 GHz. Complex permittivity spectra were fitted using Havriliak–Negami equation. By using least square fit method the dielectric parameters such as static dielectric constant ([Formula: see text]), dielectric constant at high frequency ([Formula: see text]), relaxation time [Formula: see text] (ps) and relaxation distribution parameter ([Formula: see text]) were extracted from complex permittivity spectra at 25[Formula: see text]C. The intramolecular interaction of different molecules has been discussed using the Kirkwood correlation factor, Bruggeman factor. The Kirkwood correlation factor ([Formula: see text]) and effective Kirkwood correlation factor ([Formula: see text]) indicate the dipole ordering of the binary mixtures.

Using a Multisegment Time Domain Reflectometry Probe to Determine Frost Depth in Pavement Systems

2000 ◽  
Vol 1709 (1) ◽  
pp. 108-113 ◽  
Author(s):  
Ruth L. Roberson ◽  
John Siekmeier
Keyword(s):  
Dielectric Properties ◽  
Data Collection ◽  
Time Domain ◽  
Data Interpretation ◽  
Time Domain Reflectometry ◽  
Department Of Transportation ◽  
Freezing Front ◽  
Frost Depth ◽  
Aggregate Base ◽  
Load Limits

Determining frost depth below the pavement is important for timely implementation of winter and spring load limits. Unfortunately, existing instruments such as resistivity probes, frost tubes, and moisture blocks are limited in terms of both data acquisition (automated and continuous measurements) and data interpretation. Consequently, a delay between data collection, interpretation, and dissemination of information occurs. A laboratory study was conducted by the Minnesota Department of Transportation to investigate the use of the Moisture Point probe as an instrument for locating the depth to the freezing front. The Moisture Point probe combines time domain reflectometry with remote diodeswitching to provide a profile of aggregate base and subgrade dielectric properties. From this, the frost depth can be estimated. The Moisture Point probe works well in locating the frost depth, and it improves the ability to successfully implement spring and winter load limits. This method also provides the opportunity to validate air temperature–based models that are currently used to set spring and winter load limits.

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