SU1430828A1 - Apparatus for measuring viscosity - Google Patents

Abstract

The invention is intended to measure the viscosity of liquid media. In order to increase the reliability and accuracy of measurements, the contact of the sensitive element with the measured medium is excluded. In a viscosity measuring device containing a jet tube located above the surface of the monitored liquid, an oscillation frequency meter, in the center of the end of which a jet tube is installed, a generator and a measuring circuit consisting of a detector, a low-pass filter, a pulse shaper and a frequency meter, a frequency meter the oscillations are made in the form of a two-lined one-sided converter with an uneven electrostatic field, the power lines of which begin on the same lining, capture the trace ( deepening) in a liquid formed by a gas jet and terminate on another facing. The internal lining of the converter is grounded, and the external is connected through a separation capacitance to the potential output of the RF generator and to the detector input, with the plates of the one-way converter located relative to each other with a gap decreasing to the center giving a field concentrated in the recess. 2 Il. (L. &Amp; d o 00

Description

The invention relates to a measuring technique, in particular, to devices for measuring the viscosity of liquid media, and can be used in automatic monitoring and control systems for various technological processes.

The circuit of the invention is to increase the reliability of the device by eliminating contact with the controlled medium. .

FIG. 1 shows schematically a device for measuring viscosity; n FIG. 2 - double-lined one-way capacitive transducer with non-uniform electrostatic field.

The viscosity measuring device consists of a nozzle 1, the inlet of which is connected to the output of the pressure setting device 2 and a pressure gauge 3. A sensing element 4 is placed on the nozzle tube 1. The sensing element 4 is made of a metal cup 5, inside which is placed a dielectric washer 6 and a double lining one-sided capacitive transducer 7. The lining 8 of capacitive transducer 7 is connected to the cup 5 and grounded. The plate 9 is connected to the input 10 of the measuring circuit 11. The input 10 is connected through the capacitor 12 to the potential output of the high-frequency (RF) generator 13 and through the detector 14, the low-pass filter 15, the limiting amplifier 16 and the driver 17 pulses connected to the output of the measuring circuit 11 A frequency meter 19 is connected to the output 18. The controlled liquid 20 is in a vessel (not shown). A recess 21 is formed on the surface of the liquid from the action of the jet.

The viscosity measuring device operates as follows.

A jet of gas exits nozzle 1 and runs onto the surface of the liquid.

20, the image on the last recess

21. The surface of the fluid at the point of contact with the jet performs self-oscillations, the frequency of which is a function of the viscosity of the controlled fluid. Fluctuations of the liquid surface at the point of contact with. gas jet accompanied by a change in the shape of the recess.

The sensing element 4, which perceives a change in the shape of the recess, is a capacitive transducer consisting of a metallic

Q

five

about 5 Q ..

five

0

Whose cup 5, inside of which is placed a dielectric washer 6, insulating it from a double-lined capacitive converter with an uneven electrostatic field between the plates 8 and 9. The plate 8 connected to the cup 5 is under low potential, and the plate 9 is under high potential due to connections through the separation tank 12 with the output 10 of the RF generator 13..

The arrangement of the plates 8 and 9 is selected so that the lines of force of the electrostatic field formed between them begin on one plate, capture the oscillating depression and end on the other plate. Moreover, due to the fact that the distance between the plates decreases to the center of the transducer, the field is concentrated in the region of the oscillating recess.

The change in the shape of the recess leads to a change in the capacitance between the plates 8 and 9. The change in capacitance occurs with the frequency of self-oscillations of the surface of the liquid. The converter is included in the capacitive divider arm formed by the converter's own capacitance and capacity 12. An RF voltage modulated in amplitude according to the law of capacitance variation of the converter with a frequency of self-oscillations of the fluid is detected by the detector 14 and enters the low-pass filter 15, the output of which envelops HF voltage

Next, the low-frequency oscillations are fed to the limiting amplifier 16 and the pulse shaper 17, where rectangular video signals are formed with a frequency equal to the frequency of self-oscillations of the liquid. The frequency of the rectangular video pulses is measured by a frequency meter 19. The pressure at the inlet nozzle 1 is set by the setpoint 2 and monitored by a pressure gauge 3.

Since in the proposed device there is no contact of the sensitive element with the controlled medium, the possibility of film formation and adhesion of the analyzed product is excluded, and the fire and explosion safety and reliability of the device is increased.

Claims (1)

Invention Formula A device for measuring viscosity, containing a jet tube located above the surface of the monitored fluid, an oscillation frequency meter, in the center of the end of which a jet tube is installed, a generator and a measuring circuit consisting of a series-connected detector, a low-pass filter, a pulse former and a frequency meter, so that, in order to improve the reliability of the device by eliminating contact with the controlled medium, the oscillation frequency meter is made in the form of a two-unit unilateral capacitive transducer, the inner lining of which is grounded, and externally connected through a separating capacitor to the potential generator code and to the detector input. clearance, decreasing to the center. Citta / rniiu gas f FIG. 1 2