FIELD: measuring instruments; humidity detection.
SUBSTANCE: UHF method for controlling the humidity of solid materials by a Brewster's angle consists in placing a material under test into a high-frequency electromagnetic field followed by recording changes in parameters that characterise the high-frequency radiation. A low-power diode UHF-generator is used, the wavelength tuning range of which is λg = 0.0045...0.0065 m. A real part ε'c and an imaginary part ε"c of the complex dielectric constant of the material's surface layer are calculated from the value of the diode UHF-generator wavelength λgmin ensuring minimum of the reflected power Prefl.min. The average value of the surface layer humidity Ws is determined from known formulas, the value of the imaginary part of the material's dielectric constant ε" is determined from the value of the refracted wave power Prefr and the average humidity W of the material is determined by the volume of interaction.
EFFECT: improving the sensibility and increasing the accuracy of measurement, enhancing the electromagnetic security, simplification of the hardware implementation and reduction of the mass and dimensions parameters of the device.
1 dwg
