Electromagnetic Aquametry: Electromagnetic Wave Interaction with Water and Moist Substances

ISBN-13: 9783540222224 / Angielski / Twarda / 2004 / 530 str.

K. Kupfer; Klaus Kupfer

Opis

Mformation about a material can be gathered from its interaction with electromagnetic waves. The information may be stored in the amplitude, the phase, the polarisation, the angular distribution of energy transportation or the spectral characteristics. When re trieved from the wave, certain material properties may thus be determined indirectly. Compared on the one hand to direct material analysis, an indirect method requires calibration and is prone to interference from undesired sources. On the other hand, however, it permits the determination of features inaccessible by direct methods, such as non-destructive material interrogation, high measurement speed, or deep penetration depth. However, being a physical method, the use of electromagnetic waves is still handicapped by the lack of acceptance by many chemists, who are used to applying direct approaches. Historically, the first application of electromagnetic wave interaction with mat ter involved measurement of amplitude changes at a single frequency caused by material properties, and it is still used today by some systems. This approach was soon supplemented by single frequency phase measurements, in order to avoid distortions through amplitude instabilities or parasitic reflections. Such single pa rameter measurements of course require dependence only on one variable in the measured process and sufficient stability of all other ancillary conditions. If that is not the case, the single parameter measurement fails."

Spis treści

Dielectric Properties of Water and Moist Substances.- Electromagnetic Wave Interactions with Water and Aqueous Solutions.- Water in Polymers and Biopolymers Studied by Dielectric Techniques.- Thermal and Geometrical Effects on Bulk Permittivity of Porous Mixtures Containing Bound Water.- Model Systems for Materials with High Dielectric Losses in Aquametry.- Moisture Measurement in Multi-Layered Systems.- Recent Developments in Electromagnetic Aquametry.- Measurement Methods and Sensors in Frequency Domain.- Methods of Density-Independent Moisture Measurement.- Microwave and RF Resonator-Based Aquametry.- Density and Moisture Measurements Using Microwave Resonators.- Microwave Semisectorial and Other Resonator Sensors for Measuring Materials under Flow.- Microstrip Transmission- and Reflection-Type Sensors Used in Microwave Aquametry.- A Blind Deconvolution Approach for Free-Space Moisture Profile Retrieval at Microwave Frequencies.- Sensors for Soil, Substrates, and Concrete Based on the MCM100 Microchip.- Measurement Methods and Sensors in Time Domain.- Advanced Measurement Methods in Time Domain Reflectometry for Soil Moisture Determination.- Simulations and Experiments for Detection of Moisture Profiles with TDR in a Saline Environment.- Combined TDR and Low-Frequency Permittivity Measurements for Continuous Snow Wetness and Snow Density Determination.- Principles of Ultra-Wideband Sensor Electronics.- Methods and Sensors for Quality Assesment to Products of Agriculture, Food, and Forestry.- Permittivity Measurements and Agricultural Applications.- Determination of the Composition of Foodstuffs Using Microwave Dielectric Spectra.- Microwave Dielectric Properties of Hevea Rubber Latex, Oil Palm Fruit and Timber and Their Application for Quality Assessment.- Application of Nuclear Magnetic Resonance.- Moisture Measuring with Nuclear Magnetic Resonance (NMR).

Blurb

This book covers all aspects of Electromagnetic Aquametry. It summarizes the wide area of metrology and its applications in electromagnetic sensing of moist materials. The physical properties of water in various degrees of binding interacting with electromagnetic fields is presented by model systems. The book describes measurement methods and sensors in the frequency domain, TDR-techniques for environmental problems, methods and sensors for quality assessment of biological substances, and nuclear magnetic resonance techniques. Environmental sciences, as well as civil and geoengineering, fossil fuels, food and pharmaceutical science are the main fields of application. A very wide frequency sprectrum is used for dielectric measurement methods, but the microwave range is clearly dominant. Multiparameter methods as well as methods of principal components and artificial neural networks for density independent measurements are described.