Improved differential Ka band dielectrometer based on the wave propagation in a quartz cylinder surrounded by high loss liquid under test

Abstract

The differential dielectrometer was designed to measure small differences in complex permittivity (CP) of two high loss liquids at frequency 32.82 GHz. The measurements are fully computer-aided with the exception of liquids filling and draining in the measurement cells. The time of one measurement cycle does not exceed 3 min. The dielectrometer is easy-to-work and can be used under the conditions of scientific and industrial physical–chemical laboratories. The sensitivity of the difference in the phase coefficients of the electromagnetic waves propagated in the measurement cells is better than 0.05% and that of the attenuation coefficient is of the order of 0.2%. The dielectrometer contains two measurement cells that are dielectric quartz cylinders surrounded by high loss liquids. We developed the CP calculation algorithm using the known CP of the reference liquid and the difference coefficients of complex wave propagation in the cells. The origins of the measurement errors are studied in detail and recommendations were made to avoid some of them. The dielectrometer can be used to express the identification of wine and must authenticity by means of their CP values. The CP measurement results for solutions of some substances that make wine and must composition are obtained. The possibility of using the dielectrometer for the detection of added water in wines or musts is shown.

Circular Layered Waveguide Use for Wideband Complex Permittivity Measurement of Lossy Liquids

“…4, the curves shows the dependences of the normalized phase, h nm /(k 0 ε 1 ) = h nm /k quartz , and attenuation, h nm (dB/cm), coefficients of the waveguide modes on the frequency for the radius b = 10 mm with a cylindrical quartz insert of the radius a = 2.5 mm, surrounded by the layer of water. (2), (4), H E 21 (5), and E H 21 (6). For comparison, the modes of the circular metal waveguide of the radius a = 2.5 mm, completely filled with quartz, are shown.…”

“…In our dielectrometer [5], we use a differential cavity consists of two identical cells. It uses for the measurement of small CP changes of high loss liquids under text at a fixed frequency.…”

“…We have been engaged in studying the possibility of dielectrometry to address the control of natural wines and juices. In particular, it has been shown that the method of dielectrometry is more efficient in comparison with already known detection methods of water dilution in wines and juices [5], [6].…”

“…Earlier, we have used a thick layer (the layer thickness is much more than an operating wavelength) of a fluid in the development of the methodology and the design of the cell for measuring the dielectric constants of strongly absorbing liquids at a fixed frequency [5], [21]. The cell of [5] can be regarded as a prototype of the cell described in this paper.…”

“…The cell of [5] can be regarded as a prototype of the cell described in this paper. The studied electromagnetic structure has a complex mode structure and a careful analysis of the spectrum of the waves, as well as ways of the working mode efficient excitation, is required before proceeding to the construction of the measuring cell.…”