A method for detection of powder materials in metallic hollow structures using microwaves
Artikel i vetenskaplig tidskrift, 2008

This paper presents a method for detection of the presence of small amounts of solids (powders, granules, etc.) inside metallic structures such as process vessels and containers. The method is based on propagation of microwave electromagnetic (EM) energy inside the structures and analysing the complex reflection coefficient Gamma represented by the scattering parameter S-11. 3D EM simulations were used to predict the behaviour of S for structures of rectangular, circular, and conical shapes, contaminated with materials with weak dielectric properties. The suggested method sensitivity and the effects of the material size and its distribution were assessed and results presented of comparisons of simulations and measurements. This paper demonstrates the ability to detect very low levels of contamination, e.g. of the order of 0.01-0.03 parts of a reference vessel's volume of one (e.g. length = 1 cm, width = 0.5 cm, and height = 2 cm) for materials with weak dielectric properties. This sensitivity is even better in terms of volume ratio (contamination/vessel's volume) for structures with bigger volumes and contaminants with stronger dielectric properties e.g. wet powders. The method is fully scalable for vessels with different sizes. Therefore industrial application of the method to physical processing of pharmaceutics, food, agriculture and others is envisioned. (C) 2007 Elsevier Ltd. All rights reserved.

Multidisciplinary

Engineering

Instruments & Instrumentation

Författare

Lubomir Gradinarsky

Chalmers, Institutionen för radio- och rymdvetenskap, Avancerad mottagarutveckling

Olle Nyström

Chalmers, Institutionen för radio- och rymdvetenskap, Avancerad mottagarutveckling

Victor Belitsky

Chalmers, Institutionen för radio- och rymdvetenskap, Avancerad mottagarutveckling

S. Folestad

AstraZeneca AB

Vessen Vassilev

Chalmers, Institutionen för radio- och rymdvetenskap, Avancerad mottagarutveckling

Measurement: Journal of the International Measurement Confederation

0263-2241 (ISSN)

Vol. 41 6 637-646

Ämneskategorier

Elektroteknik och elektronik

DOI

10.1016/j.measurement.2007.09.002