UHF METHOD FOR MEASURING SURFACE MOISTURE LEVEL OF SOLID MATERIALS, MOISTURE LEVEL BASED ON VOLUME OF INTERACTION, NORMAL TO THE SURFACE OF MOISTURE GRADIENT AND DEVICE FOR REALIZATION OF SAID METHOD Russian patent published in 2007 - IPC G01N22/04 

FIELD: technology for determining moisture level of solid materials, possible use in construction, chemical and other industrial branches.

SUBSTANCE: UHF method for determining moistness of solid materials from Bruster angle includes placing material being researched into high frequency electromagnetic field with following registration of alteration of parameters, characterizing high frequency radiation. Spherical two-surface multi-slit antenna with electronically controlled directional diagram excites an electromagnetic wave falling onto dielectric material. Inclination angle of directional diagram is changed until moment when minimal power of reflected wave is observed in closed volume of receiving section of antenna, length of UHF generator wave is determined and Bruster angle is calculated. Then on basis of given mathematical formulae, value of moistness of surface layer of material being measured is calculated. Further, power of refracted wave is stabilized by changing power of falling wave, temperature T₁ inside the volume of antenna is measured on the surface of material. Then UHF generator is transferred to mode for generation of radio impulses having constant duration, amplitude and repeat frequency, number of video impulses is counted. When given temperature T₂ is achieved, number of generated video impulses is recorded and moistness value is determined in volume of material from given mathematical relation. On basis of measured moistness values of surface layer and moistness in material volume, average moistness alteration coefficient along normal to material surface is determined. Device for realization of aforementioned method contains UHF generator, UHF detector, wave conducting Y-circulator, inlet shoulder of which additionally includes block of generator controlled by voltage, attenuator, controlled by microprocessor, UHF heat-variable resistor-based watt meter with output to microprocessor device for controlling and stabilizing output power, diode impulse modulator and generator of video impulses, controlled by microprocessor, peak detector. First output shoulder of Y-circulator includes absorbing synchronized load, and second output shoulder includes spherical two-surface antenna, positioned in internal volume of which is second UHF heat-variable resistor-based watt meter, mated with extreme digital controller for finding and indicating minimum of power of reflected wave, and with resonator sensor of wave meter. Powering of UHF generator is realized by means of microprocessor power block, video impulses counter is mated with digital wave meter, and block of thermo-couples is mated with microprocessor device.

EFFECT: increased sensitivity, increased precision of measurement of moisture level of surface layer, expanded functional capabilities due to additionally determined integrated moisture normally to surface inside the material, and also decreased parasitic UHF radiation.

2 cl, 3 dwg