SU1566271A1 - Gas-content transducer - Google Patents

Abstract

The invention relates to power engineering and can be used to control the fuel supply systems of power plants. The purpose of the invention is to improve accuracy. The gas content sensor consists of a metal pipe / UMT / 1 section for accommodating the material to be studied. On the side wall of the UMT 1, communication elements 2 are made for connecting a rectangular waveguide 3 of the measuring unit. To seal the structure, part of the waveguide 3 is filled with dielectric 4. At the ends of UMT 1, there are two grids of conductive plates 5 and 6 with a given length and a distance between them. When the gas content in the fluid filling the cavity resonator formed by UMT 1 and plates 5 and 6 changes, its dielectric constant and, consequently, the resonant oscillation frequency changes. At this frequency, gas content in the liquid is judged. 3 il.

Description

The invention relates to energy and can be used to control the fuel supply systems of power plants.

The purpose of the invention is to increase accuracy.

Fig. 1 is a diagram of a gas content sensor; Fig. 2 (a, b) of the transducer circuit with a gas content sensor in the load circuit of the autogenerator and measurement of the resonance frequency of the gas content sensor; in fig. 3 - graphs of the dependence of the resonant frequency of the gas content sensor on the degree of gas content in the test material (kerosene).

The gas content sensor consists of a metal pipe section 1 for accommodating the material under study, communication elements 2, made in the side wall of a metal pipe section 1 for connecting a measuring unit. Elements 2 can be made in the form of slots in the common wall of section 1 of the metal pipe and rectangular waveguide 3 of the measuring unit. 1 of the conducting plates 5 and 6 and the distance between them h are related by the ratio

tgЈ

Where

L v

Max

2, tg &

4T

Max

- maximum knowledge

The dielectric constant and loss tangent of the material under study are measured, L is the length of section 1 of the metal pipe, y is the wavelength. The axes of the elements 2 are located in a plane passing through the axis of the section 1 of the metal pipeline and perpendicular to the conductive faces 5 and 6.

The measuring transducer circuit (Fig 2a) includes a sensor 7, an auto-oscillator 8, a frequency meter 9.

The measurement circuit for the resonance frequency of the gas-content sensor includes a tunable microwave generator 10, a microwave valve 11, a power divider 12, and a power meter 13.

five

0 5 0 5

0

50

55

The device (Fig „2b) works as follows.

The generator 10 excites in the sensor 7, which is a cavity resonator formed by the section 1 of the metal pipe and gratings, electromagnetic oscillations. Through the element 2, the oscillations from the sensor 7 through the power divider are fed to the power meter 13 and the frequency meter.

9. Tuning frequency generator

10, find the resonant frequency of the main type of oscillations (NP1) by the maximum amplitude of the field in the resonator. When measuring the gas content in the fluid filling the resonator, its dielectric constant and, consequently, the resonant oscillation frequency (n) changes. The measurement accuracy depends on the steepness of the amplitude characteristic of the resonator, i.e. from its good quality. The high quality factor of the resonator is achieved by installing at its ends two groups of plates 5 and 6, the dimensions of which are determined by the relation (1). Choosing the sizes of plates 5 and 6 from relation (l), we transform this set of plates into a set of transcendental waveguides, in which the electromagnetic waves attenuate and the reflection occurs from the ends. Oscillations are excited in the resonator in such a way that the electric field lines intersect the diametrical plane of the resonator passing through the communication apertures at a right angle.

The device, the circuit of which is shown in FIG. 2a, works as follows. Through element 2, the microwave generator 8 excites the sensor 7, the reactance of which affects the generation frequency, is used to judge the gas content in the liquid.

Claims (1)

Invention Formula A gas content sensor containing a portion of a metal conduit for accommodating a material under investigation, communication elements formed in a side wall of a portion of a metallic conduit for connecting a measuring unit, characterized in that, in order to improve accuracy, two grids of conductive plates are inserted parallel to the axis of the metallic tru5 156627I and installed at its ends, while the length of the conductive plates 1 and the distance between them h are related by  T-5E-) 2. 8 + + Ј e & JT  A -2 k maxi where Јand „„ A, tg 0 - maximal znamaks chene dielectric constant and tangent loss angle of the studied material; L is the length of the section of the metal pipeline; - wavelength, The axes of the communication elements are located in the plane passing through the axis of the metal pipe section perpendicular to the conducting plates, while the grids and the metal pipe section form a resonator. 2 101520.0 Gaosodermanie (/ o) Put.3