Electromagnetic moisture measurement technologies have proven to be valuable tools in diverse applications. This monograph covers basic aspects of nondestructive electromagnetic methods of water content determination and relates to the associated highly multidisciplinary field of research and development. It also presents a comprehensive selection of relevant field-tested methods and instruments. The fundamentals of electromagnetic field interactions with dipolar materials are briefly discussed, with special attention towards the dielectric properties of water and aqueous solutions. A tutorial and overview of electromagnetic measurement methods is presented, including dielectric spectroscopy in broad frequency and time domains, as well as dielectric imaging techniques. This review is complemented by a demonstration of successful real-world implementations for the moisture determination of soils, snow, buildings and building materials, food and agricultural goods, as well as various industrial products. The text is completed by a guide concerning the use of reference liquids for the calibration of sensors and instrumentation and by a bibliography of more than 850 references. The monograph is useful as a reference book for researchers and engineers and as a textbook for upper-level students interested in the water content determination of materials.

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.

Moisture analysis covers a variety of methods for measuring high levels of moisture, as well as trace amounts, in solids, liquids, or gases. There are many applications where trace moisture measurements are indispensable for manufacturing and for process quality assurance. Trace moisture in solids must be controlled for plastics, pharmaceuticals and heat treatment processes. Measurement applications in gases and liquids include, for example, drying processes, hydrocarbon processing, pure gases in the semiconductor industry, natural gas pipeline transport, the conditioning of food and other products. Written by experts with over 20 years of experience in the field, this one-stop guide covers all aspects of these measurements, including both the theory and a wealth of practical know-how. As such, it includes guidelines on installation, on the realization of standards for absolute and relative humidity, verification and traceability measurements, equipment calibration methods and the latest research developments. Backed by numerous case studies, this practical book serves the needs of those working in the industry tasked with performing or developing new techniques and processes for moisture and humidity measurement. As a result, the scientist or engineer has all the information required for accurate, reliable, economically viable and efficient moisture measurement.

The first book to address all theoretical and practical aspects of electromagnetic wave interaction with water and moist materials, this unique book features 29 full-length, peer-reviewed papers prepared by 69 of the world's experts in aquametry for a key Workshop held in conjunction with the IEEE MTT-S International Microwave Symposium in Atlanta, Georgia, 1993. Collectively, the papers illustrate the physical background of microwave techniques used for moisture content determination, present stimulating examples of applications of microwaves for nondestructive and accurate measurements, and demonstrate successful implementation of techniques in a variety of industries.

This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, and finally, the biological effects and medical applications of electromagnetic fields.