SU1125530A1 - Capacitive pickup of gaseous and liquid media dielectric properties - Google Patents

Abstract

1. CAPACITIVE SENSOR OF DIELECTRIC PROPERTIES OF GAS- AND LIQUID MEDIA, containing electrodes connected to output terminals, which are different in that, in order to simplify its design and increase the specific capacitance, the electrodes are made of flexible metal single-stranded or multi-strand wires. tia and arbitrarily laid in a ball. 2. The sensor according to claim 1, that is, and with the fact that each of the wires is connected at both ends to the same terminal. (L tc sd sd oo

Description

1 The invention relates to epi- tial tehiyus and can be used to create analytic instruments for liquid-to-gaseous materials. To determine their dielectric properties, dielectric properties directly or. indirectly characterize the quality of the mega-ter1-alov. for example, the humidity of the gas is 1 SHI dielectric hfc. A capacitive sensor is known, which is an electrical capacitor, electrode; which have a strict definable geometric shape, for example, planar-parallel plates. The electrodes of the capacitor are connected to the output terminals of the terminal. The sensor is two-way: connected to the measuring probe, Eosprodes have a rigid fixation of the mutual arrangement of the sensor housing, which is achieved through insulation holders, gaskets. PECHNIC ELEMENTS 1.1 3 Closest to the offer; o;: y is a capacitive sensor of the dielectric properties of gas and liquid media containing electrons, g: 1Ts connected to the output terminals. Electr; 5yds of the sensor are made in the form of two packs of coaxial electrodes, fixed in the sensor body by means of two cross-shaped bases interconnected by an isolator with L - rods. The disadvantage of the known sensor is the considerable complexity of the design. As for: the manufacture of electrodes and the electrode holder requires special equipment and equipment, and: - the reciprocal arrangement of the electrodes B the sensor body must be performed with high accuracy Besides. the known sensor is characterized by a low value of the specific capacitance (m, e, capacity, per unit volume); which is caused by the difficulty in completing the gap between the electrodes. Therefore, in terms of economically acceptable design considerations 5 and dimensions, the total useful capacitance of the sensor is only 10-100 pF. which is commensurate with the gharasite e: micros of connecting wires and creates difficulties in the design of capacitance to measuring devices, in which the sensor, according to the operating conditions 02, must be removed from the measuring circuit IIIou. The objective of the invention is to simplify the design to a new one, not a specific capacity, the Decree. the goal is achieved TeMj-g; o and the capacitive sensor of the dielectric properties of gaseous and liquid; infrared environments containing electrodes; sub; very close to terminals; electrodes are made of flexible metal.:; these are solid or; multicore about olKg coating with insulation and arbitrariness. laid) in a ball. Except for each wire of two codes and connected to the same terminal. FIG. The proposed sensor is shown; Fig. 2 shows the dependence of e.1ectr; 1 sensor capacitance on dl .1vschloch {y s electrodes at a constant sm) density; on F1-; Гь 3 - dependency of the tectrical capacitance g; atchik from the capacity to see the electrode with a constant initial length of the wires. Sensor Soyrlskt Kortgus 1 (Fig. 1) fvOiopbiH has VP. and the discharge of the dutter stream of flow of control material. In the wall of the housing 1 two output terminals are fixed: Pech-LMU 2, KOTOpbEviv sensors -: connected to the measuring circuit (not shown). K.ch terminal 2 on the inner side of the hull wall I of the gyon-joint. At one end of the bending is Mei allic wire 3j lying surface isotop. The conical surface 5 of the coils of which are arbitrarily tied into a ball and located in the cavity of the housing 1, and free, to it; about the wire, are in the total mass of coils of each other. Change over a wide range The length of the wires and the density of see 5 of the coils 5 can change the initial sensor's width over a wide range. Fig. 2 shows the dependence of the capacitance of the sensor on the wire length of the npii blocks and other different conditions (see ball coil and constant wire diameter). The wires are made from copper sdnozhi.pnogo obmoto.nogo .prozop. Pakova pnoshnosalnoy isolation, for example, the type of PEL 0.38, and ot.M.YATYa coil ggaovolov, h-.vl: sichykh electrodes is chosen such that gaps remain between the wires. These gaps are of a fairly complex configuration and form an interelectrode space. As can be seen from Fig. 3, when the initial length of the wire cord is 20 m (performed with PEL wire 0.38) and when the density of the coil smith varies from 2 10 to 3.5 10 g / m, its capacity varies from 1300 up to 2000 pF. This circumstance allows the sensor to be identified during mass production, the capacitance value is nominal by the necessary change in the density of the cm (compressing or stretching the coil of wire electrodes J. The flexibility of the wires allows the manufacture of sensors of various spherical shapes (Fig. 1), cylindrical conic, etc., appropriately wire into a ball of ttey or some other shape. DG works as follows: Sensor under investigation (gas or liquid), flowed through the body cavity, filled The gap between the wire electrodes, forming an electrical capacitor, whose capacitance, other conditions being equal, depends on the dielectric properties of the medium in the interelectrode space, is filled in. When the dielectric constant changes, the capacitance of the sensor changes, which is recorded by the measuring circuit. without a case, when, according to the measurement conditions, the ball is immersed (placed) directly in the test environment. The principle of the sensor operation does not change if the sensor electrodes are made of a bundle of metal wires having a surface insulation coating and laid in a ball with the necessary density of smith. The principle of operation of the proposed sensor also does not change if each of the wires, PVC ends are connected to the same terminal. The advantage of the proposed sensor in comparison with the known is the possibility of smooth adjustment of its initial capacity. Smooth changes in capacitance over a wide range are achieved by varying the density of a see of a coil of wire electrodes, i.e. by changing the size of the gaps between them,

Ck

pf 2000

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ft 2.5

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Fiz.Z

Claims (2)

1. CAPACITIVE SENSOR OF DIELECTRIC PROPERTIES OF GAS AND LIQUID MEDIA, containing electrodes · connected to output terminals, characterized in that, in order to simplify its design and increase the specific capacitance, the electrodes are made of flexible metal single-core or multicore wires coated with insulation and randomly tangle. 2. The sensor according to p. ^ Characterized in that each of the wires with two ends is connected to the same terminal. Figure 1