SU347648A1 - METHOD FOR DETERMINING THE MATERIAL MOISTURE - Google Patents

Description

The invention relates to the field of moisture measurement and can be used to measure moisture, for example, fabric or leather.

According to the proposed method for determining the moisture of a material by passing microwave oscillations through it, the material under investigation is placed along the direction of propagation of microwave energy at an angle to the incident vector of electric field intensity and the position of the transmitted vector in space is measured. This makes it possible to increase the sensitivity of the measurements.

FIG. 1 is a schematic diagram of a device enabling the proposed method to be implemented; FIG. Figure 2 shows the locus of the linearly polarized vector of the transmitted wave.

The test material I is placed between the transmitting 2 and receiving and indicator 3 antennas. Power is supplied to the transmitting antenna from generator 4 via a calibrated attenuator 5.

The method is implemented in the following order.

The transmitting antenna (in particular, the horn) 2 emits a linearly polarized plane wave, the vector of the electric field strength which is oriented in the XOZ plane.

F - F -X-:

- - max about

 - the complex amplitude of the vector of intensity of the electric field of the incident wave;

max is the amplitude value of the electric field intensity vector;

XQ - single ort; Y a-f / (3 - constant distribution

waves;

and Ke {y} is the attenuation coefficient; p 1 „d ;; (, {7} is the phase coefficient. Spreading in space, where

the material under study is located, the vector can be represented as two components,

one of which is E- parallel to the material under study, and the other + is perpendicular. 5 For them, the ratio

For the component En, the coefficient a is zero and in the material under study this component does not decay; for component

E-, and depends on the location of the position indicator of the transmitted wave E- is not equal to n, and the resulting vector of the transmitted wave, u

changes its nozholenpe relative to E + at an angle of 6 5-10 °. Thus, by selecting the power of the incident wave, it is possible to achieve a change in the position of the vector of the transmitted wave fnp relative to + from zero for an absolute dry material to 45 ° for the case of complete absorption of component E. in accordance with the change in humidity of the material under study. The position indicator of the transmitted wave vector is designed as a receiving horn with a detector section rotating around its axis.

The position of the vector is determined by the position of the minimum of the vector's hodograph, which makes it possible to use the method of two readings widely used in microwave engineering to improve the accuracy of determining the vector in space and, accordingly, to increase the accuracy of determining the humidity of the material under study.

Subject invention

A method for determining the moisture content of a material, for example, fabric, leather, by passing microwave oscillations through it, characterized in that, in order to increase the accuracy of measurements, the material under study is positioned at an angle to the incident vector of electric voltage and measure its position in space which is a measure for measuring humidity.

FIG.

h.ZH

, Rh / i,

Phi