RU2584923C1 - Device for measuring electrical resistance of earth - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to power industry, particularly to construction of overhead transmission lines and earthing devices. For designing and construction of power transmission lines surveys are carried out, wherein location is surveyed, characteristics of soil are determined, including electric resistance of soil. For measuring of soil electrical resistance in pit disclosed is simplified design of measuring device consisting of two articulated symmetric bent rods. On rods measuring electrodes, sockets and wires connecting them are fixed. For measuring device is installed in pit, measuring devices are connected, rods are pulled to pit walls by means of handle, electrodes are embedded into soil, and measurements are conducted. Proposed is to measure electric resistance directly in pit before installation of support, and use measurement results during assembly of grounding device.

EFFECT: high accuracy of measuring electrical resistance of soil, reduced weight of measuring device and time spent for measurements.

1 cl, 2 dwg

Description

The invention relates to the electric power industry, in particular to the construction of overhead power lines and grounding devices.

A device for measuring the electrical resistivity of the earth (patent RU No. 2284531, 06/15/2005), comprising a dielectric tube equipped with ring current and measuring electrodes connected by independent conductors to the output contacts, and a rack for a screw clamp rod with a disk electrode.

The disadvantage of this device is the need, before it is immersed in the ground, to prepare a sample of the earth for measurements, which causes significant difficulties when measuring at depths commensurate with the depth of the pits, for the supports of power lines. Measurement technology requires a lot of work and time.

It is also known a device for measuring the electrical resistivity of the earth (patent RU No. 2334991, 04/12/2007), which contains current measuring electrodes, racks for electrodes and a platform for installing the device in the center of the foundation pit for a support, on which a rack with guides for electrodes, stops and retaining plate. The electrodes, moving along the guides, are embedded in the walls of the pit, form contact with different layers of the earth in a horizontal plane.

The disadvantage of this device is the complexity of its design and installation in the pit, the ability to measure only on one side of the pit, which makes it difficult to use when the walls of the pits are curved and transport between supports in the field.

The closest in technical essence and the achieved technical result to the proposed technical solution is a device for measuring the electrical resistivity of the earth in pits for power transmission line supports (patent RU 2338214; 06/29/2007 - prototype), which contains a base plate with limiters and a frame on which guides are fixed. A shaft with handles is mounted in the center of the base plate with the possibility of rotation, on which worm gears are fixed in the boxes, which engage with the electrodes by means of teeth. The frame and shaft are equipped with control couplings, and wires with clamps are connected to the electrodes.

The disadvantage of this device is the significant mass, the inconvenience of its transportation along the route of the overhead line, installation and removal from the pit.

The technical result is to increase the accuracy of measuring the electrical resistance of the earth, reducing the weight of the measuring device and the time spent on measurement.

The technical result is achieved in that the device for measuring the electrical resistance of the earth, containing electrodes, wires and measuring instruments, according to the invention consists of two symmetrically curved rods connected by a hinge, on each of which electrodes are fixed, electrical wires in a protective box, plug sockets , handles, while along the edges and in the places of bending of symmetrically curved rods, holes are made for installing electrodes in the working or transport positions, and the rods with are interconnected by a hinge located in the center of the rod segment between the lower and middle electrodes connected in a single structure so that during measurements the connection is on the vertical axis of the foundation pit and all the electrodes abut against its opposite walls, and a measurement scale is located in the upper part of the rods the depths of the pit.

The novelty of the device lies in the possibility of folding the structure due to the presence of a swivel, in the possibility of its free placement in the pit and in the possibility of introducing electrodes into the walls of the pit by means of the extension of the rods using the handles for taking readings from measuring instruments. In addition, the use of this device allows you to measure the earth resistance in each pit in layers, in its vertical section, before installing the support, and also take into account all local features and the topography of the earth when determining the structural dimensions of the grounding device and choosing its location.

The essence of the invention is illustrated by drawings, where figure 1 shows a General view of the device, and figure 2 - its cross section in working condition.

The device consists of two symmetrically curved rods 2, interconnected by a hinge 3 (Fig. 1), on each of which are fixed electrodes 4, electrical wires in a protective box 6, plug connectors 5, handles 7, while on the edges and in the places of bending symmetrically curved rods 2 made holes 8 for installing the electrodes 4 in the working or transport positions. In the upper part of the rods 2 is a scale 9 for measuring the depth of the pit 1.

The device works as follows: on the ground, in accordance with the project, pit 1 is drilled (Fig. 2), the rods 2 are brought together by the arms 7 (Fig. 1) and the device is placed in the pit 1 in its center, then the rods 2 are bred by the arms 7 opposite sides before the electrodes are installed in the working position (penetration into the walls of the pit 1), measuring devices are connected to the plug connectors 5. Next, the operator takes the readings from the instruments in a layer-by-layer measurement of the resistivity of the earth in the pit 1. Based on the measurement results, the design parameters of the grounding device for a specific support are determined.

Using the present invention in comparison with known devices of a similar purpose, it is possible to measure the resistance of the earth to electric current directly in the pit and layer by layer in areas adjacent to the base of the support, to choose the most rational design and location of the grounding device, spending minimal labor and financial resources. The device can be assembled in transport and working condition, which facilitates its transportation and operation, while the mass of the device is several times less than the prototype.

The claimed device improves the accuracy of measurements of the electrical resistance of the earth, reduces the mass of the measured device and the time spent on measurement.

Claims (1)

A device for measuring the electrical resistance of the earth, containing electrodes, wires and measuring instruments, characterized in that it consists of two symmetrically curved rods connected by a hinge, on each of which are fixed electrodes, electrical wires in a protective box, plug connectors, handles, while along the edges and in the places of bending of symmetrically curved rods, holes are made for installing electrodes in the working or transport positions, the rods being interconnected by a hinge, located nym in the center of the segment of rod between the lower and middle electrodes, united in a single structure so that the connection has been in the measurements on the vertical excavation axis and all the electrodes rested on its opposite wall, and the top of the rod is a scale for measuring the depth of excavation.

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