SELF-MAINTAINED DIELCOMETRIC TRANSDUCER AND METHOD OF DIELECTRIC CHARACTERISTICS MEASURING USING SELF-MAINTAINED DIELCOMETRIC TRANSDUCER (VERSIONS) Russian patent published in 2009 - IPC G01R27/26 G01N27/02 

FIELD: electricity.

SUBSTANCE: group of inventions may be used to monitor material parametres having effects on their dielectric characteristics (humidity, density, physical and chemical components, structural content and additives content) and, particularly, to measure humidity and electrical conductivity in soil at one time or humidity avoiding density effects or to measure humidity and grain or forage grass density. The self-maintained transducer with primary sensing device included into oscillatory circuit of the self-maintained transducer, consists of an oscillation-controlled intensifier included into the circuit of positive feedback. The positive feedback circuit is represented as a resistor-oscillatory circuit divider being placed between intensifier input and output. The intensifier has linear amplitude characteristic and independent input of intensifier control. The self-maintained transducer is provided with a circuit of oscillation inertial confinement at linear section of amplitude characteristics. The above mentioned linear section includes amplitude detector and elements to connect detector with oscillation intensifier control input. The said elements realise negative feedback of oscillation amplitude along oscillation amplitude envelope. The transducer has outputs to measure self-induced oscillations and voltage in the middle point of divider or at amplifier control input. The first version of the device provides for the self-maintained transducer containing capacitive transducer in the parallel oscillatory circuit. On the contrary, there is an inductive transducer in parallel or series-oscillatory circuit in the second version. Measuring methods are also proposed by the invention using devices described in the first and second versions.

EFFECT: separate measuring of integrated dielectric permeability and electric conductivity in tested material at minor errors; avoidance of individual amplitude characteristic effects on measured values and production of normalised transducer characteristics during duplication of self-maintained dielcometric transducers.

38 cl, 28 dwg, 6 tbl