APPARATUS FOR DETERMINING DENSITY OF LIQUID MEDIA BY MEASURING FREQUENCY OF SELF-OSCILLATING STRING SYSTEM Russian patent published in 2024 - IPC G01N9/00 G01N11/16 

FIELD: measurement technology.

SUBSTANCE: invention relates to the technique of measuring density of liquid media by measuring the frequency of natural oscillations of a string electronic-mechanical self-oscillating system, a string–working medium, which is directly immersed in the analyzed medium. Device can be used in oil refining and other industries, including at explosive gas stations, gas stations, oil depots, chemical and food industry facilities, where it is necessary to carry out regular and operational control of density of liquefied hydrocarbons, including fuels and lubricants. String oscillating system is formed by an electronic-mechanical self-oscillating system with feedback piezoelectric positive coupling, made in the form of a thin metal string, consisting of three sections—upper section, central working section and lower section. Working section of string is placed in magnetic field of permanent magnet, which upper end through a triangular prism is mechanically connected to a piezoelectric transducer connected to the input of the preamplifier of sinusoidal oscillations, output of which is connected to the input of the power amplifier, the ungrounded output of which is connected to the electronic frequency meter and through the three-channel connector to the holder of the upper end of the upper section of the string, and the grounded output of the power amplifier is connected through the grounded fixed roller blocks to the lower end of the working section of the string. Lower end of the lower section of the string is fixed to the working body, which provides the required tension of the string due to the force of gravity of the latter.

EFFECT: high accuracy of measuring density of liquids.

5 cl, 7 dwg