Current probe and grounding resistance measuring instrument

Abstract

The utility model provides a current probe and a grounding resistance measuring instrument, which comprise a current probe body, a liquid adding funnel is arranged at the top end of the current probe body outside soil, a plurality of liquid outlet holes are arranged at the part of the current probe body inside the soil, the liquid adding funnel is communicated with the liquid outlet holes, and the liquid outlet holes are arranged at intervals along the axial direction of the current probe body. The liquid adding funnel is detachably connected with the piston rod, the conductivity of soil around the probe can be actively regulated and controlled to improve the accuracy and stability of grounding resistance measurement, conductive liquid is injected into the soil around the current probe through the liquid adding funnel, the soil contact resistance is remarkably reduced, and the accuracy and stability of grounding resistance measurement are improved. The liquid diffusion range and the permeation speed can be controlled through the arranged liquid outlet holes, and local supersaturation or waste is avoided, so that the stability of a current loop is ensured, and the measured data is closer to a real grounding resistance value; under pressurization of the piston rod, liquid can evenly permeate into soil layers of different depths, and low-water-resistance pits formed by local water accumulation are avoided.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of lightning protection detection, and specifically relates to a current probe and a grounding resistance measuring instrument. BACKGROUND

[0002] The grounding resistance measuring instrument is a resistance measuring device, which is used for measuring the grounding resistance of various devices and the conductor resistance value of low resistance in the departments of electric power, post and telecommunication, railway, communication, mine and the like, and can also measure the soil resistivity and ground voltage.

[0003] The grounding resistance measurement is an important means for evaluating the safety of grounding systems such as power systems, communication base stations and lightning protection devices of buildings. The core principle is to inject a test current (I) into the grounding electrode (E) and measure the voltage drop (V) between the grounding electrode and the remote earth, so as to calculate the grounding resistance (R = V / I). The traditional measurement method (such as three-pole method and four-pole method) depends on the correct arrangement of the current probe (C) and the potential probe (P), wherein the current probe is responsible for establishing the test current loop, and its performance directly affects the measurement accuracy.

[0004] At present, the current probe on the market mainly adopts a metal rod, such as a copper-coated steel or a galvanized steel, which is directly inserted into the soil, but in dry or high-resistance soil, such as the arid region in northwest China, the soil is mainly gray desert soil, saline soil and sandy soil. The current probe has poor contact with the soil, and the measurement accuracy is significantly affected. For example, in the Changji Hui Autonomous Prefecture of Xinjiang, the soil conductivity survey data of the Changji Meteorological Bureau in recent years shows that the volume resistivity of the typical soil in this region can reach 10 4 Ω·m in a dry state, which is much higher than that in the humid eastern region (usually 10

[0005] When the galvanometer sensitivity of the grounding resistance measuring instrument is insufficient, it may not be able to accurately capture the weak current signal. At this time, the soil along the current probe is wetted, which can improve the stability of the current loop, make the galvanometer more easily reach the equilibrium state, improve the measurement accuracy, enhance the conductivity between the current probe and the soil, and reduce the contact resistance between the current probe and the soil. However, the amount of water for watering is not easy to control. If the water is excessively poured, the water will locally accumulate to form a low-resistance "water pit", so that the current is concentrated in the wet area instead of being uniformly distributed, resulting in a lower measured grounding resistance value and failing to reflect the true situation. If the water is not sufficiently poured, the water only stays in the upper part of the contact between the probe and the soil, and the lower part of the contact between the probe and the soil is still insufficiently wet, which reduces the conductive channel between the probe and the soil particles, significantly increases the contact resistance, and causes a large error in the measurement data. UTILITY MODEL CONTENTS

[0006] In view of the deficiencies in the prior art, the utility model provides a current probe and grounding resistance measuring instrument, and aims to solve the technical problem of how to control the water injection amount and penetration depth when water is injected into the soil to reduce the contact resistance between the current probe and the dry soil.

[0007] The technical scheme of the present application is:

[0008] A current probe, comprising a current probe body, a liquid adding funnel is arranged at the top end of the current probe body outside the soil, a part of the current probe body inside the soil is provided with a plurality of liquid outlet holes, the liquid adding funnel is communicated with the liquid outlet holes through a channel arranged in the current probe body, the liquid outlet holes are arranged at intervals along the axial direction of the current probe body, and a piston rod for pressurized water injection is detachably connected to the channel. The conductivity of the soil around the probe can be actively regulated to improve the accuracy and stability of the grounding resistance measurement, the liquid adding funnel is arranged to inject conductive liquid into the soil around the current probe, which significantly reduces the soil contact resistance, the liquid diffusion range and penetration speed can be controlled through the liquid outlet holes, local oversaturation or waste is avoided, thereby ensuring the stability of the current loop, and the measurement data is closer to the true grounding resistance value; under the pressurization of the piston rod, the liquid can uniformly penetrate into soil layers at different depths, avoiding the formation of low-resistance water pits caused by local water accumulation, and facilitating the later dredging and cleaning of the liquid outlet holes.

[0009] Further, the liquid outlet hole is conical, the hole diameter of the liquid outlet hole close to the channel is larger than the hole diameter of the liquid outlet hole away from the channel, and the risk of reverse blockage of soil particles is reduced.

[0010] Further, the bottom of the piston rod is provided with a rubber plug, and the rubber plug is in interference fit with the channel.

[0011] Further, the current probe body is provided in parallel with at least two, a conductive connecting rod is connected between the current probe bodies, the total contact area of the plurality of current probes arranged in parallel with the soil is increased by more than times, the overall contact resistance is significantly reduced, and the current distribution is more uniform, when a single current probe is in poor contact, the redundant current probe can still maintain the loop, avoiding interruption of measurement, and the plurality of current probes arranged in parallel have high reliability and strong adaptability.

[0012] Further, the bottom end of the current probe body is provided with a sharp part, the bottom end of the sharp part is provided with a through hole communicated with the channel, and the through hole facilitates the later cleaning of silt and prevents blockage.

[0013] Further, the bottom end of the current probe body is detachably connected with a sharp part, the bottom end of the channel is communicated to the top end of the sharp part, and after use, the sharp part can be detached, facilitating the later cleaning of silt remaining in the liquid outlet hole and preventing blockage.

[0014] Further, the liquid adding funnel side wall is provided with a capacity scale, which facilitates quantitative control of liquid adding amount, and the current probe body is provided with a height scale, that is, when the scale line is completely buried in the soil, the current probe body insertion depth is qualified.

[0015] Further, the current probe body or the conductive connecting rod is provided with a jack for inserting a lead wire, which can be quickly plugged and unplugged, improving operation efficiency and facilitating storage.

[0016] Further, the diameter of the current probe body is the same as that of the conductive connecting rod, and the end of the lead wire is connected with a wire clamp, which is clamped on the current probe body or the conductive connecting rod, so that the use is convenient and fast.

[0017] A kind of grounding resistance measuring instrument, including the current probe body.

[0018] The specific beneficial effects of the utility model include:

[0019] 1, the utility model can actively regulate and control the conductivity of soil around probe to improve the accuracy and stability of grounding resistance measurement, the conductive liquid is injected into the soil around current probe by the liquid adding funnel arranged, the soil contact resistance is significantly reduced, the liquid diffusion range and penetration speed can be controlled by the liquid outlet hole arranged, local supersaturation or waste is avoided, so that the current loop is stable, and the measurement data is closer to the real grounding resistance value;

[0020] 2, under the pressure of piston rod, liquid can be uniformly penetrated into soil layers of different depths, local water accumulation is avoided to form low resistance pit, and the liquid outlet hole is convenient for later dredging and cleaning;

[0021] 3, the total contact area of multiple current probes arranged in parallel and soil is increased by more than times, the overall contact resistance is significantly reduced, and the current distribution is more uniform, when a single current probe is in poor contact, the redundant current probe can still maintain the loop, so that the measurement is not interrupted, multiple current probes are designed in parallel, the reliability is high, and the adaptability is strong. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model, the drawings needed in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can obtain other drawings according to these drawings without creating creative labor.

[0023] Figure 1 It is a schematic view of embodiment 1 in the utility model;

[0024] Figure 2 It is a schematic view of embodiment 2 in the utility model;

[0025] Figure 3 For Figure 1 Enlarged view at A in Figure 1;

[0026] Figure 4 For the schematic diagram of embodiment 3 in the utility model.

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 1, liquid adding funnel;

[0029] 2, liquid outlet hole;

[0030] 3, current probe body;

[0031] 4, piston rod;

[0032] 5, tip;

[0033] 31, electrically conductive connecting rod;

[0034] 32, channel;

[0035] 33, wire;

[0036] 34, wire clamp;

[0037] 41, rubber plug. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0039] The embodiment 1 is a current probe, which comprises a current probe body 3, a liquid adding funnel 1 arranged at the top end of the current probe body 3 outside the soil, a plurality of liquid outlet holes 2 arranged at the part of the current probe body 3 inside the soil, the liquid adding funnel 1 is communicated with the liquid outlet holes 2 through a channel 32 arranged in the current probe body 3, and each liquid outlet hole 2 is arranged along the axial direction of the current probe body 3. The conductivity of the soil around the current probe body 3 can be actively controlled to improve the accuracy and stability of the grounding resistance measurement. The conductive liquid is injected into the soil around the current probe body 3 through the liquid adding funnel 1, which significantly reduces the soil contact resistance. The liquid diffusion range and penetration speed can be controlled through the liquid outlet holes 2, so as to avoid local oversaturation or waste, thereby ensuring the stability of the current loop and the measurement data is closer to the true grounding resistance value. The channel 32 is detachably connected with a piston rod 4 for pressurized water injection. The outer wall of the piston rod 4 is attached to the inner wall of the channel 32. Under the pressure of the piston rod 4, the liquid can uniformly penetrate into the soil layer at different depths, avoiding the formation of low-resistance water pits caused by local water accumulation.

[0040] The funnel 1 arranged at the top of the current probe body 3 realizes convenient and controllable liquid injection through a simple structure. When measuring in the field, if it is necessary to add liquid such as brine to the soil around the probe, an additional container usually needs to be carried, which is cumbersome and easy to spill. The liquid adding funnel 1 is directly integrated at the top of the current probe body 3, without the need for additional tools, and the conductive liquid can be directly poured into the liquid adding funnel 1. The liquid outlet of the liquid adding funnel 1 is communicated with the current probe body 3, and the liquid can be directly delivered to the deep part of the current probe body 3 inserted into the soil along the outer wall or the internal channel of the probe.

[0041] Specifically, as shown in Figure 3 , the liquid outlet hole 2 is designed as a tapered hole or a structure with a large inner diameter and a small outer diameter. The hole diameter of the liquid outlet hole 2 close to the channel 32 is larger than the hole diameter of the liquid outlet hole 2 far from the channel 32, which reduces the risk of reverse blockage of soil particles. Preferably, as shown in Figure 1 , the liquid outlet hole 2 is arranged in a staggered spiral around the current probe body 3, so that the liquid is uniformly exuded in 360°, and the liquid directly penetrates into the soil layer at different depths, forming a stable low-resistance area around the current probe, ensuring that the current diffuses more uniformly from the probe to the soil, and reducing the measurement error.

[0042] Specifically, the bottom of the piston rod 4 is provided with a rubber plug 41, which is in interference fit with the channel 32. The elastic deformation of the rubber plug 41 can tightly attach to the inner wall of the channel 32, forming a reliable seal. When the liquid is added to the liquid adding funnel 1, the liquid flows downward under the action of gravity. The liquid outlet speed of the liquid outlet hole 2 is slow, and the overflow liquid is concentrated in the liquid outlet hole 2 close to the bottom. When the piston rod 4 is pressed down, the liquid outlet speed of the liquid outlet hole 2 is accelerated, and the overflow liquid is not only concentrated in the liquid outlet hole 2 close to the bottom, but also makes the diffusion and penetration of the liquid more uniform.

[0043] Specifically, the bottom end of the current probe body 3 is provided with a sharp part 5 for facilitating insertion into the soil, and the bottom end of the sharp part 5 is provided with a through hole in communication with the channel 32, through which the liquid flows downward by gravity and is uniformly distributed around the current probe body 3. The through hole facilitates later cleaning of the residual silt in the liquid outlet hole 2 with clean water to prevent clogging.

[0044] Specifically, the side wall of the liquid adding funnel 1 is provided with a capacity scale for facilitating quantitative control of the liquid adding amount. The current probe body 3 is provided with a height scale. Generally, the current probe body 3 needs to be buried in the soil by 40 cm. The length of the current probe body 3 is greater than 40 cm. The height scale is set at the position of 40 cm. That is, when the scale line is completely buried in the soil, the insertion depth of the current probe body 3 is qualified.

[0045] After the measurement is completed, the current probe body 3 is dried in time to prevent rusting.

[0046] Specifically, the current probe body 3 or the connecting rod 31 is provided with a jack for inserting the plug of the lead wire 33. When the plug is inserted into the jack, the current is turned on, the measurement starts, and the plug can be quickly inserted and pulled out, thereby improving the operation efficiency. After use, the lead wire 33 is separated from the current probe body 3, and the lead wire 33 is not easily entangled and overlapped, thereby facilitating storage. The above embodiment is a mature prior art and a conventional technical means known to those skilled in the art.

[0047] A grounding resistance measuring instrument comprising the current probe body 3.

[0048] Embodiment 2, as a preferred embodiment, is different from embodiment 1 in that a current probe comprises a current probe body 3. The top end of the current probe body 3 located outside the soil is provided with a liquid adding funnel 1, and the part located in the soil is provided with a plurality of liquid outlet holes 2. The liquid adding funnel 1 is in communication with the liquid outlet holes 2 through a channel 32 arranged in the current probe body 3. The liquid outlet holes 2 are arranged along the axial direction of the current probe body 3. The conductivity of the soil around the current probe body 3 can be actively regulated to improve the accuracy and stability of the grounding resistance measurement. The conductive liquid is injected into the soil around the current probe body 3 through the liquid adding funnel 1, which significantly reduces the soil contact resistance. The liquid diffusion range and penetration speed can be controlled through the liquid outlet holes 2 to avoid local oversaturation or waste, thereby ensuring the stability of the current loop and the measurement data being closer to the true grounding resistance value. The channel 32 is detachably connected with a piston rod 4 for pressurized water injection. The outer wall of the piston rod 4 is in close contact with the inner wall of the channel 32. Under the pressure of the piston rod 4, the liquid can uniformly penetrate into the soil layers at different depths to avoid the formation of low-resistance water pits.

[0049] Preferably, at least two current probe bodies 3 are arranged in parallel, and a conductive connecting rod 31 is connected between the current probe bodies 3, such as Figure 2As shown, the three current probe bodies 3 are arranged in parallel in a triangular shape. The contact resistance of a single probe with the soil can be high, and parallel connection can significantly reduce the total resistance. The total contact area of the three current probe bodies 3 arranged in parallel with the soil is increased by more than three times, significantly reducing the overall contact resistance and making the current distribution more uniform. When a single current probe body 3 has poor contact, the redundant current probe body 3 can still maintain the loop to avoid measurement interruption. The three current probes arranged in parallel in a triangular shape have high reliability and strong adaptability through contact area multiplication and redundant configuration.

[0050] When the measurement is completed, the current probe body 3 is dried in time to prevent rusting.

[0051] Embodiment 3, as a preferred embodiment, differs from embodiment 2 in that the diameter of the current probe body 3 is the same as the diameter of the conductive connecting rod 31. The diameter of the current probe body 3 is the same as the diameter of the conductive connecting rod 31. The end of the wire 33 is connected with a wire clamp 34, as shown in Figure 4 The wire clamp 34 is clamped on the current probe body 3 or the conductive connecting rod 31.

[0052] Specifically, the wire clamp 34 is in the shape of a U and is detachably connected with the current probe body 3 or the conductive connecting rod 31, which is convenient and fast to use. The above-mentioned embodiments are mature prior art and are conventional technical means known to those skilled in the art.

[0053] Embodiment 4, as a preferred embodiment, differs from embodiment 1 in that a current probe includes a current probe body 3. The top end of the current probe body 3 located outside the soil is provided with a liquid feeding funnel 1, and the part located in the soil is provided with a plurality of liquid outlet holes 2. The liquid feeding funnel 1 is in communication with the liquid outlet holes 2 through a channel 32 arranged in the current probe body 3. Each liquid outlet hole 2 is arranged along the axial direction of the current probe body 3. The conductivity of the soil around the current probe body 3 can be actively controlled to improve the accuracy and stability of the grounding resistance measurement. The conductive liquid is injected into the soil around the current probe body 3 through the liquid feeding funnel 1, which significantly reduces the soil contact resistance. The liquid diffusion range and penetration speed can be controlled through the liquid outlet holes 2 to avoid local supersaturation or waste, thereby ensuring the stability of the current loop and the measurement data being closer to the true grounding resistance value. The piston rod 4 for pressurized water injection is detachably connected with the channel 32. The outer wall of the piston rod 4 is in close contact with the inner wall of the channel 32. Under the pressure of the piston rod 4, the liquid can uniformly penetrate into the soil layer at different depths to avoid the formation of low-resistance water pits.

[0054] A funnel 1 is arranged on the top of the current probe body 3, which realizes convenient and controllable liquid injection through simple structure. When field measurement is needed, if liquid such as brine needs to be added to the soil around the probe, an additional container usually needs to be carried, which is cumbersome and easy to spill. The liquid adding funnel 1 is directly integrated on the top of the current probe body 3, without the need for additional tools, and the conductive liquid can be directly poured into the liquid adding funnel 1. The liquid outlet of the liquid adding funnel 1 is in communication with the current probe body 3, and the liquid can be directly delivered to the deep part of the current probe body 3 inserted into the soil along the outer wall or the internal channel of the probe.

[0055] Specifically, as shown in Figure 3 The liquid outlet hole 2 is designed as a tapered hole or a structure with a large inner diameter and a small outer diameter. The hole diameter of the liquid outlet hole 2 near the channel 32 is larger than the hole diameter away from the channel 32, which reduces the risk of reverse blockage of soil particles. Figure 1 Preferably, as shown in Figure 1 The liquid outlet hole 2 is arranged around the current probe body 3 in several staggered spirals, so that the liquid is uniformly exuded in 360 degrees, and the liquid directly penetrates into the soil layers at different depths, forming a stable low-resistance area around the current probe, ensuring that the current spreads more uniformly from the probe to the soil, and reducing measurement errors.

[0056] Specifically, the bottom of the piston rod 4 is provided with a rubber plug 41, which is in interference fit with the channel 32. The elastic deformation of the rubber plug 41 can tightly fit the inner wall of the channel 32, forming a reliable seal. When liquid is added to the liquid adding funnel 1, the liquid flows downward under the action of gravity. The liquid outlet speed of the liquid outlet hole 2 is slow, and the overflow liquid is concentrated near the bottom of the liquid outlet hole 2. When the piston rod 4 is pressed down, the liquid outlet speed of the liquid outlet hole 2 is accelerated, and the overflow liquid is not only concentrated near the bottom of the liquid outlet hole 2, but also makes the diffusion and penetration of the liquid more uniform.

[0057] Specifically, the bottom end of the current probe body 3 is detachably connected with a sharp part 5, which is in threaded fit with the current probe body 3. The bottom end of the channel 32 is in communication with the top end of the sharp part 5. After use, the sharp part 5 can be detached, and the water can flow from the liquid adding funnel 1 into the channel 32, and then flow out from the bottom of the liquid outlet hole 2 and the channel 32, which is convenient for later cleaning of the silt and prevents blockage.

[0058] Specifically, the side wall of the liquid adding funnel 1 is provided with a capacity scale, which is convenient for quantitative control of the liquid adding amount. The current probe body 3 is provided with a height scale. Usually, the current probe body 3 needs to be buried in the soil by 40 cm, and the length of the current probe body 3 is greater than 40 cm. The height scale is set at 40 cm, that is, when the scale line is completely buried in the soil, the insertion depth of the current probe body 3 is qualified.

[0059] After the measurement is completed, the current probe body 3 is dried in time to prevent rusting.

[0060] The utility model discloses not exhaustive place is the conventional technical means of the person skilled in the art.

[0061] The above shows and describes the basic principle, main features and beneficial effects of the utility model. The above is only a preferred embodiment of the utility model, and does not limit the utility model. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A current probe comprising a current probe body (3), characterized in that: The top end of the current probe body (3) located outside the soil is provided with a liquid adding funnel (1), and the part located in the soil is provided with a plurality of liquid outlet holes (2). The liquid adding funnel (1) is communicated with the liquid outlet holes (2) through a channel (32) arranged in the current probe body (3). Each liquid outlet hole (2) is arranged along the axial direction of the current probe body (3) at intervals. The channel (32) is detachably connected with a piston rod (4) for pressurized water injection.

2. The current probe of claim 1, wherein: The liquid outlet hole (2) is conical, and the hole diameter of the liquid outlet hole (2) close to the channel (32) is larger than the hole diameter of the liquid outlet hole (2) away from the channel (32).

3. The current probe of claim 2, wherein: The bottom of the piston rod (4) is provided with a rubber plug (41), and the rubber plug (41) is in interference fit with the channel (32).

4. The current probe according to any one of claims 1-3, characterized in that: The current probe body (3) is arranged in parallel with at least two, and a conductive connecting rod (31) is connected between the current probe bodies (3).

5. The current probe of claim 3, wherein: The bottom end of the current probe body (3) is provided with a sharp part (5), and the bottom end of the sharp part (5) is provided with a through hole communicated with the channel (32).

6. The current probe of claim 3, wherein: The bottom end of the current probe body (3) is detachably connected with the sharp part (5), and the bottom end of the channel (32) is communicated to the top end of the sharp part (5).

7. The current probe according to any of claims 1-3, 5-6, characterized in that: The side wall of the liquid adding funnel (1) is provided with a capacity scale, and the current probe body (3) is provided with a height scale.

8. The current probe of claim 4, wherein: The current probe body (3) or the conductive connecting rod (31) is provided with a jack for inserting the plug of the lead wire (33).

9. The current probe of claim 8, wherein: The diameter of the current probe body (3) is the same as the diameter of the conductive connecting rod (31), the end of the lead wire (33) is connected with a wire clamp (34), and the wire clamp (34) is clamped on the current probe body (3) or the conductive connecting rod (31).

10. A ground resistance measuring instrument, characterized by: The current probe body (3) comprises the current probe body (3) according to any one of claims 1-9. The current probe body (3) comprises the current probe body (3) according to any one of claims 1-9.

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