SU1296917A1 - Device for measuring electrical conductivity of liquid flow - Google Patents

Abstract

The invention can be used for a wide class of conductometric studies of ocean dynamics, in hydrodynamics and also in metrology as an exemplary means of calibration and calibration of conductometers-meters. The goal is to increase accuracy and spatial resolution. The device contains a generator, contactless conductometric sensor and recorder. An additional ring electrode connected via a potentiometer to the additional winding of the sensor transformer connected to the generator is installed in the dielectric attachment mounted on the sensor housing in the through-hole. 4 il. with b (L Nd with 0); oh

Description

The invention relates to hydrophysical measurements and can be used in conductometry for non-follow-up ocean dynamics, in experimental hydrodynamics for measuring turbulence parameters, in metrology as an exemplary means for calibrating and calibrating working tools for measuring average and pulsation values of electrical conductivity (CEE). ).

The purpose of the invention is to improve the accuracy and spatial resolution.

Fig. 1 is a schematic of a device for measuring the electrical conductivity of fluid flows; Fig.2-4 shows the distribution patterns of the power lines and equipotentials of the electric field in the sensitive area of the sensor with a different ratio of the values of the potentials on the ring electrode and the hub.

The device contains a sinusoidal voltage generator 1, a conductometric contactless sensor 2 and a recorder 3, sensor 2 consists of a housing 4 made in the form of a dielectric rotating body with a flow pipe 5 along the axis of rotation. Two toroidal transformers 6 and 7 are located in case 4 covering flow tube 5

The metal concentrator 8 flashes the inner surface of the tube 5 and the outer part of the housing 1, having a gap in the plane where the dielectric attachment 9 is fixed to the housing, Hole 10 in the packing is equal in diameter to the diameter of the flow tube 5, and the ring electrode 11, the First transformer 6 is connected to the generator 1 and provided with an additional winding 12, one end of which is connected to the hub 8 of the outer surface of the housing 4 and with the movable contact of the potentiometer 13, epodvizhnye contacts of which are respectively connected to the ring electrode 11 and the second end of the auxiliary winding 12, The second transformer 7 is connected to the recorder 3,

The device works as follows.

The fluid fills tube 5 and closes the turn of the connection of transformers 6

and 7, The signal of the generator 1 through the transformer 6 in the turn of the connection leads to an emf causing a current, whose value is proportional to the CEC

fluid. The recorder 3, using transformer 7, converts this current value into a signal (or a numerical reading), convenient for monitoring or further processing,

In the absence of voltage

electrode 11 (FIG. 2) the potential of this electrode (V) acquires a value equal to some natural potential (Vg) existing in this

the region due to the distribution of the electric field in the conducting medium between the inner (conditionally, the potential is zero) and the outer (V) edges of the hub

, (one)

those. and, ue. At the same time, the electrode 11 has almost no effect on the processes occurring when converting the value of the CEC flux into an electrical signal in the sensor 1. The distribution of the field in a conducting medium obeys the Laplace equation

7 and oh

(2)

where V is the Laplace transform operator j 5 and is the potential,

т, е, possesses homogeneity concerning potential. Therefore, the electric field pattern in the sensor can be regarded as quasi-stationary, 0.

When a certain voltage is applied to the electrode 11, the amplitude is somewhat lower than the natural potential

| uJ / Ue /. (3)

the distribution of the electric field in the area of

0 of the electrode 11. In this case, an additional field arises between the electrode 1 1 and the external edge of the hub 8, the coherent main field whose power lines are directed to the same

5 side as the main floor

(FIG. 3, hatched area). This leads to two physical phenomena: near the inlet of the nozzle 10, the lines of the main

312

an electric field (between the edges of the concentrator 8) of the sensor 1, between the electrode 1 1 and the tension edge of the concentrator 8 some additional current begins to flow in the liquid

An electrolytic (conductive) fluid is a second-series conductor with an ionic conduction mechanism and the behavior of charge carriers in the presence of an electric field in a fluid is described through their mobility. Due to the viscous nature of the flow of carriers, their direction and speed strictly coincide with the direction and magnitude of the vector electric field strength in a liquid (according to the charge sign). Therefore, the hatched area in FIG. 3 corresponds to the area of flow of ion current between electrode 11 and the outer edge of the concentrator 8. Since the parameters of the medium (liquid) are almost unchanged under the action of an applied electric field, and the cross section of the conductive channel in the area of the nozzle opening is reduced the resistance between the edges of the concentrator 8 along the fluid circuit increases, which leads to a decrease in the current in it with a constant potential difference at the edges of the concentrator 8 (a single turn of the transformer Ator 6). Thus, using the potential of the electrode 11, the conductive sensor 1 (A) is controlled by the contactless method

.-

-A.and "A f (U ,,)

where - the value of UEP fluid;

1, is the current flowing between the edges of the concentrator 8 through the liquid and measured by the recorder 3; A - conductive constant

sensor.

If the potential of the electrode 11 (Fig. 4) decreases, a moment (V, | 0) may occur when the additional electric field completely blocks the inlet of tube 5 and the current flowing between the edges of the hub 8 stops completely.

In the specified area of change of the potential of the electrode 11 near the inlet 10 of the nozzle 9 on the flow side outside the housing

2969

and .j

o and o 35

25

thirty

40

174

Yes 1-chica 1 is induced by a narrow, capillary-type conductive channel in which the eye: 1 almost all the resistance of the communication circuit is concentrated. At the same time, surface tension forces characteristic of narrow capillary channels in solids are completely absent. Due to the large value of the resistance of the capillary, the influence of surface effects on the edges of the concentrator is eliminated, despite the relatively large diameter of the tube 5.

Example. As housing 4, a standardized part of a serially mounted sensor was used. Toroidal transformers 6 and 7 were filled on the magnetic cores. The internal diameter of the flow tube 2 was 16 mm. The dielectric nozzle was made of plexiglass with a built-in annular electrode at a distance of 1 mm from the edge of the inlet. When the potential on the electrode changed from O (inner edge of the concentrator) to the natural value (75 mV, when applied to the entire concentrator of an induced emf of 100 mB), an equivalent narrowing of the conducting channel was recorded. The change in the total resistance of a coil in a fluid with an ECO value of 1 Ω / m was from 200 (the natural potential of the electrode) to 10,000 Ω (the potential of the electrode is equal to the potential of the inner edge of the concentrator). The registrar 3 recorded artificially created irregularities along the sensor axis, having a diameter of 0.5-1 mm. The frequency of the generator is 16 kHz, the number of turns of each transformer is 50, the voltage of the generator is 5 V,

45

five

Claims (1)

Invention Formula A device for measuring the electrical conductivity of fluid flows, comprising a generator, a recorder and a contactless conductometric sensor consisting of a housing made in the form of a dielectric streamlined rotational body with a flow tube axially enclosed by two toroidal transformers placed in a housing mounted on the dielectric nozzle housing with hole, and a metal hub, located on the inner surface of the tube with the transition to the outer surface of the housing, and g generator of the registrar and connected respectively to nepsoNry and second transformers, characterized in that, in order to increase the accuracy and spatial resolution, nozzle The first transformer is provided with an additional winding, one end of which is connected to a concentrator and a movable tip of a potentiometer, which are connected to the ring electrode and volts respectively. provided with a ring electrode, at the end of an additional winding. on the inner surface of the hole and having a diameter equal to the diameter of the flow tube, and the first transformer is provided with an additional winding, one end of which is connected to a hub and a moving contact of a potentiometer, the fixed contacts of which are connected respectively to the ring electrode and the second 1 m cpuz.2 fig.Z Editor N.Kishtulinets Compiled by Y. Korshunov Tehred I. Pspovich Order 769/45 Circulation 777 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 C) Proofreader N.Korol