DEVICE DETERMINING DIELECTRIC PERMITTIVITY OF LIQUID Russian patent published in 2002 - IPC

FIELD: measurement technology, measurement of moisture content in liquid oil products. SUBSTANCE: device includes cylindrical cavity resonator on which axis pipe-line with analyzed liquid is positioned. Retuned SHF generator is coupled with output through coupler to communication loop with cavity resonator. Device has reference SHF generator and mixer on which first output signal from reference SHF generator and on which second output signal from output of coupler are fed. Resonator has second communication loop. Communication loops are placed in the middle of length and planes of their opening are arranged at angle of 45 degrees with respect to axis of resonator. There also are amplitude detector, analog-to-digital converter connected in series. Converter is coupled with its output to first information input of microprocessor to which second information input signal from output of frequency-to-code converter is supplied. Input of frequency-code converter is connected with its input to output of mixer. Output of digital-to-analog converter is connected to control input of retuned SHF generator and its output is coupled to control output of microprocessor. EFFECT: raised accuracy of determination of dielectric permittivity thanks to elimination of confusion of types of oscillations and correction of temperature error caused by change of linear dimensions of cavity resonator. 2 dwg