CN111141785B - Soil resistivity measuring device, method and storage medium - Google Patents
Soil resistivity measuring device, method and storage medium Download PDFInfo
- Publication number
- CN111141785B CN111141785B CN202010121326.5A CN202010121326A CN111141785B CN 111141785 B CN111141785 B CN 111141785B CN 202010121326 A CN202010121326 A CN 202010121326A CN 111141785 B CN111141785 B CN 111141785B
- Authority
- CN
- China
- Prior art keywords
- soil
- inner electrode
- electrode
- radius
- circumference
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/041—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
- Y02A90/30—Assessment of water resources
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
The utility model relates to a soil resistivity measuring device, a method and a storage medium, comprising: a wheatstone bridge circuit; the Wheatstone bridge circuit comprises four bridge arms; one of the four bridge arms comprises a first end, a second end, an inner electrode and a plurality of outer electrodes; the inner electrode and the plurality of outer electrodes are respectively inserted into the soil to be measured, and the depth of the inner electrode and the depth of the outer electrodes inserted into the soil to be measured are the same; the plurality of outer electrodes are uniformly distributed on the circumference taking the central axis of the inner electrode as the center of a circle and are electrically connected in sequence through wires, and the wires are connected with the first end after being connected in a tail-to-tail mode; the inner electrode is connected with the second end; and determining the resistance value of the soil to be measured based on a Wheatstone bridge balance principle, and determining the resistivity of the soil to be measured based on a uniform electric field model formed by the inner electrode and the outer electrode. The beneficial effects of the utility model are as follows: the field construction is convenient to carry out simple and quick measurement, and the resistivity of the land in the area to be measured can be determined more quickly and conveniently without complex calculation.
Description
Technical Field
The utility model belongs to the technical field of resistivity measurement, and particularly relates to a soil resistivity measurement device, a soil resistivity measurement method and a storage medium.
Background
At present, two methods are adopted for earth electricity measurement, namely, a standard model is adopted for sampling, and a voltammetric diode wiring method or a quadrupole wiring method is adopted for measuring the resistivity, wherein the measuring method has the defects that sampling and actual measurement have deviation, and inaccurate test results are easy to cause; secondly, measuring the field resistivity by adopting a volt-ampere quadrupole wiring method and combining a correction method; however, this method requires an infinite level of ground, a uniform isotropic conductive medium filled under the ground, and the apparent resistivity alone is measured because these conditions are not actually satisfied, i.e., the actual resistivity cannot be accurately measured within a certain range.
Disclosure of Invention
In order to solve the problems of complex measurement and limited applicable field in the prior art, the utility model provides a soil resistivity measuring device, a soil resistivity measuring method and a storage medium, and the soil resistivity measuring device and the soil resistivity measuring method have the characteristics of simple measurement, low cost, wide application range and the like.
A soil resistivity measuring device according to an embodiment of the present utility model includes: a wheatstone bridge circuit;
the Wheatstone bridge circuit comprises four bridge arms;
one of the four bridge arms comprises a first end, a second end, an inner electrode and a plurality of outer electrodes;
the inner electrode and the plurality of outer electrodes are respectively used for being inserted into the soil to be tested, and the depth of the inner electrode and the depth of the outer electrodes inserted into the soil to be tested are the same;
the outer electrodes are uniformly distributed on the circumference taking the central axis of the inner electrode as the center of a circle and are electrically connected in sequence through wires, and the wires are connected with the first end after being connected in a tail-to-tail mode;
the inner electrode is connected with the second end;
determining the resistance value of the soil to be measured between the inner electrode and the outer electrode based on the balance condition of the Wheatstone bridge circuit;
a resistivity formula based on a uniform electric field formed between the inner electrode and the outer electrode:
determining resistivity, wherein R is the resistance value of the soil to be detected, and h is the depth of the inner electrode and the outer electrode inserted into the soil to be detected; r is (r) 1 R is the radius of the inner electrode 2 Is the radius of the circumference.
Further, the soil resistivity measuring device further includes: the singlechip is used for acquiring voltage change values delta V at two ends of a ammeter in the Wheatstone bridge circuit and is based on the following steps:
Further, the number of the external electrodes satisfies:
Further, the radius of the circumference satisfies:
Further, the inner electrode and the outer electrode are steel nails with the same specification.
The soil resistivity measuring method according to the embodiment of the utility model is applied to the soil resistivity measuring device, and comprises the following steps:
acquiring the radius of the inner electrode and the radius of the circumference taking the central axis of the inner electrode as the center of a circle;
determining the resistance value of the soil to be measured between the inner electrode and the outer electrode based on the balance condition of the Wheatstone bridge circuit;
and determining the resistivity of the soil to be measured between the inner electrode and the outer electrode based on a coaxial cable model as follows:
Further, the number of the external electrodes satisfies:
Further, the radius of the circumference satisfies:
Further, the determining process of the resistance value of the soil to be measured comprises the following steps:
acquiring resistance values of all bridge arms in the Wheatstone bridge circuit and based on
A storage medium according to an embodiment of the present utility model stores a computer program which, when executed by a processor, implements the steps in the soil resistivity measurement method as described above.
The beneficial effects of the utility model are as follows: the uniform electric field formed by combining the inner electrode and the outer electrode through the Wheatstone bridge circuit is convenient for field construction to carry out simple and rapid measurement, the inner electrode and the outer electrode with the same depth are inserted into a plane to carry out measurement, and the resistivity of the land in the to-be-measured area can be determined more rapidly and conveniently without complex calculation.
Drawings
In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a soil resistivity measurement apparatus provided in accordance with an exemplary embodiment;
FIG. 2 is a layout of an outer electrode and an inner electrode provided in accordance with an exemplary embodiment;
FIG. 3 is a block diagram of an outer electrode and an inner electrode provided in accordance with an exemplary embodiment;
fig. 4 is a flowchart of a soil resistivity measurement method provided in accordance with an exemplary embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present utility model more apparent, the technical solutions of the present utility model will be described in detail below. It will be apparent that the described embodiments are only some, but not all, embodiments of the utility model. All other embodiments, based on the examples herein, which are within the scope of the utility model as defined by the claims, will be within the scope of the utility model as defined by the claims.
Referring to fig. 1 to 3, an embodiment of the present utility model provides a soil resistivity measuring device including: a wheatstone bridge circuit;
the Wheatstone bridge circuit comprises four bridge arms, a ammeter and a power supply, and is a circuit capable of accurately measuring resistance. R is R G The resistor plays a role of current limiting and the switch K 1 And K 2 The magnitude of the current is controlled in a matched manner to avoid the condition of overlarge or undersize current, and G is a ammeter used for checking whether the current exists in the branch circuit where the ammeter is located. When no current is flowing through G, the bridge is said to be balanced, and the resistance of the four arms satisfies a simple relationship r=r 1 R S /R 2 Utilizing this relationship while R S For adjustable resistance by adjusting R S The unknown resistance R can be measured by balancing the bridge。
One of the four legs in the wheatstone bridge circuit includes a first end, a second end, an inner electrode and a plurality of outer electrodes;
the inner electrode and the plurality of outer electrodes are respectively inserted into the soil to be measured, and the depth of the inner electrode and the depth of the outer electrodes inserted into the soil to be measured are the same;
because the soil is a poor electric conductor, a coaxial cable model is adopted to bind an electric field between the inner electrode and the outer electrode to form a uniform field model, and a plurality of outer electrodes are uniformly distributed on the circumference taking the central axis of the inner electrode as the center of a circle based on the uniform field model of the coaxial cable because the resistivity and the size of the inner electrode are irrelevant, and the outer electrodes are electrically connected in sequence through wires, and the wires are connected with the first end after being connected in an ending way; the inner electrode is connected with the second end;
the resistance value of the soil to be measured between the inner electrode and the outer electrode can be determined based on the balance condition of the Wheatstone bridge circuit;
a resistivity formula based on a uniform electric field formed between the inner electrode and the outer electrode:
determining resistivity, wherein R is the resistance value of the soil to be measured, and h is the depth of the inner electrode and the outer electrode inserted into the soil to be measured; r is (r) 1 Radius r of the inner electrode 2 Is the radius of the circumference. Therefore, when the resistivity of the land is actually tested, the Wheatstone bridge can adopt a box bridge or an self-organizing bridge, the internal and external electrodes can be inserted into a plane in the area to be tested for measurement, the principle is simple, complex calculation is not needed, the cost is low, and the application range is wider without being limited by the test site.
In order to further optimize the technical solution, in another specific embodiment of the present utility model, the method further includes: the singlechip is used for acquiring voltage change values delta V at two ends of a ammeter in the Wheatstone bridge circuit and is based on the following steps:
Specifically, the voltage between two points of different BD of the soil to be measured connected in the Wheatstone bridge circuit changes, the voltage change in the circuit can be known through collecting the voltage change, and the purpose of measurement is achieved, wherein R is as follows 1 R is arranged on two bridge arms, R 1 R will be voltage V CC Partial pressure, R on the other two arms S And R is 2 Will V CC Partial pressure, flow through R 1 The current of R is I 1 ＝V cc /(R 1 +R)，R 1 Voltage V at both ends 1 ＝R 1 *V cc /(R 1 +r); similarly, R is 2 Voltage V at both ends 2 ＝R 2 *V cc /(R 2 +R s ) The voltage difference is
Then the resistance value of the soil to be measured can be determined by obtaining the voltage difference between the two points BD through the singlechip.
It will be appreciated that those skilled in the art may increase the voltage value and the current value in the corresponding detection circuit to obtain the circuit based on the balancing principle of the wheatstone bridge circuit, and the resistance value is measured based on the balancing condition, and the present utility model is not limited herein.
In some embodiments of the present utility model, to ensure that the measured resistivity is more accurate and reliable, the requirement for the number of uniformly distributed external electrodes, i.e., the number of external electrodes, is as follows:
Meanwhile, the radius of the circumference of the outer ring is not too small, and the circumference radius meets the following conditions:
Therefore, the number of the external electrodes and the size of the circumference are limited according to the diameters of the external electrodes, and the number and the size of the circumference can be flexibly set according to the different calibers of the external electrodes when the external electrodes are used, so that the accuracy of a measurement result is ensured.
Meanwhile, when in measurement, the inner electrode and the outer electrode are the same in insertion depth, so that the inner electrode and the outer electrode are in the same horizontal plane, if the medium is uniform, the measurement result is not affected by the insertion depth, the inner electrode and the outer electrode can be made of common steel nails with the same model and specification in field use measurement, the measurement requirement can be met, the requirement of field measurement is convenient, the requirement on the measurement equipment is not high, and the local material can be obtained more suitable for the requirement of field construction.
Based on the soil resistivity measuring device provided in the above embodiment, the embodiment of the utility model shown in fig. 4 further provides a soil resistivity measuring method, which is applied to the soil resistivity measuring device in the above embodiment, and includes the following steps:
301. acquiring the radius of the inner electrode and the circumference radius taking the central axis of the inner electrode as the center of a circle;
302. determining the resistance value of the soil to be measured between the inner electrode and the outer electrode based on the balance condition of the Wheatstone bridge circuit;
303. the resistivity of the soil to be measured between the inner electrode and the outer electrode is determined based on the coaxial cable model to be as follows:
Specifically, after the measuring device is arranged in the area to be measured, the Wheatstone bridge circuit can be adjusted based on the principle of bridge balanceA varistor for zeroing the value of the ammeter to a state where the bridge is in balance, the equation r=r based on the bridge balance state 1 R s /R 2 Obtaining the soil resistance value of the measurement area, and then calculating a formula based on the resistivity of the uniform field model
The resistivity of the measurement region can be obtained. />
To ensure accurate and reliable resistivity measurements, in some embodiments, the number of outer electrodes is required to satisfy:
the radius of the circumference needs to satisfy:
As a possible implementation manner of the foregoing embodiment, in other specific embodiments of the present utility model, the determining process of the resistance value of the soil to be measured includes:
acquiring resistance values of each bridge arm in the Wheatstone bridge circuit and based on
The embodiment of the utility model also provides a storage medium, wherein the storage medium stores a computer program, and the computer program realizes each step in the soil resistivity measurement method described in the embodiment when being executed by a processor. The storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.
Specific embodiments of the storage medium provided in the embodiments of the present utility model may refer to the embodiments of the soil resistivity measurement method described in any of the above examples, and will not be described herein.
It should be noted that in the description of the present application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Furthermore, in the description of the present application, unless otherwise indicated, the meaning of "plurality" means at least two.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.
Claims (3)
1. A soil resistivity measuring device, comprising: a wheatstone bridge circuit;
the Wheatstone bridge circuit comprises a singlechip and four bridge arms;
one of the four bridge arms comprises a first end, a second end, an inner electrode and a plurality of outer electrodes;
the inner electrode and the plurality of outer electrodes are respectively used for being inserted into the soil to be tested, and the depth of the inner electrode and the depth of the outer electrodes inserted into the soil to be tested are the same;
the outer electrodes are uniformly distributed on the circumference taking the central axis of the inner electrode as the center of a circle and are electrically connected in sequence through wires, and the wires are connected with the first end after being connected in a tail-to-tail mode;
the inner electrode is connected with the second end;
determining the resistance value of the soil to be measured between the inner electrode and the outer electrode based on the balance condition of the Wheatstone bridge circuit;
a resistivity formula based on a uniform electric field formed between the inner electrode and the outer electrode:
determining resistivity, wherein R is the resistance value of the soil to be detected, and h is the depth of the inner electrode and the outer electrode inserted into the soil to be detected; r is (r) 1 R is the radius of the inner electrode 2 Is the radius of the circumference;
the singlechip is used for acquiring voltage change values delta V at two ends of a ammeter in the Wheatstone bridge circuit and is based on the following steps:
the number of the external electrodes satisfies:
the radius of the circumference satisfies:
the inner electrode and the outer electrode are steel nails with the same specification.
2. A soil resistivity measuring method, characterized in that it is applied to the soil resistivity measuring device according to claim 1, the method comprising:
acquiring the radius of the inner electrode and the radius of the circumference taking the central axis of the inner electrode as the center of a circle;
determining the resistance value of the soil to be measured between the inner electrode and the outer electrode based on the balance condition of the Wheatstone bridge circuit;
and determining the resistivity of the soil to be measured between the inner electrode and the outer electrode based on a coaxial cable model as follows:
the number of the external electrodes satisfies:
the radius of the circumference satisfies:
the determining process of the resistance value of the soil to be measured comprises the following steps:
acquiring resistance values of all bridge arms in the Wheatstone bridge circuit and based on
3. A storage medium storing a computer program which, when executed by a processor, implements the steps of the soil resistivity measurement method of claim 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010121326.5A CN111141785B (en) | 2020-02-26 | 2020-02-26 | Soil resistivity measuring device, method and storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010121326.5A CN111141785B (en) | 2020-02-26 | 2020-02-26 | Soil resistivity measuring device, method and storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111141785A CN111141785A (en) | 2020-05-12 |
| CN111141785B true CN111141785B (en) | 2023-04-25 |
Family
ID=70527983
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010121326.5A Active CN111141785B (en) | 2020-02-26 | 2020-02-26 | Soil resistivity measuring device, method and storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111141785B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111724662B (en) * | 2020-07-14 | 2022-06-07 | 云南电网有限责任公司电力科学研究院 | Soil environment electric leakage simulation system and method |
| CN114062436B (en) * | 2021-10-28 | 2023-12-22 | 甘肃省农业科学院林果花卉研究所 | Cold resistance comparison method for dormant branches of fruit trees |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201780336U (en) * | 2010-08-04 | 2011-03-30 | 中国石油化工股份有限公司 | Resin melting specific resistance measuring instrument |
| CN203299275U (en) * | 2013-04-25 | 2013-11-20 | 南方电网科学研究院有限责任公司 | Local surface conductivity measure probe apparatus for insulator |
| CN104407227A (en) * | 2014-11-05 | 2015-03-11 | 贝兹维仪器(苏州)有限公司 | Power grid pole mud resistivity measurement system |
| CN206292307U (en) * | 2016-11-16 | 2017-06-30 | 李卓昊 | A kind of device of utilization Wheatstone bridge measuring resistance |
| CN107765091A (en) * | 2016-08-18 | 2018-03-06 | 国家电网公司 | A kind of original position soil sample resistance rate measurement apparatus |
| JP2018072052A (en) * | 2016-10-26 | 2018-05-10 | 株式会社クボタ | Specific resistance measuring apparatus of soil |
| CN208488497U (en) * | 2018-07-13 | 2019-02-12 | 飞鸣科学仪器（武汉）有限公司 | A kind of conductivity electrode |
| CN110118896A (en) * | 2018-11-13 | 2019-08-13 | 清华大学 | A kind of method and system measuring stratified soil resistivity and dielectric constant frequency dependent characteristic |
-
2020
- 2020-02-26 CN CN202010121326.5A patent/CN111141785B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201780336U (en) * | 2010-08-04 | 2011-03-30 | 中国石油化工股份有限公司 | Resin melting specific resistance measuring instrument |
| CN203299275U (en) * | 2013-04-25 | 2013-11-20 | 南方电网科学研究院有限责任公司 | Local surface conductivity measure probe apparatus for insulator |
| CN104407227A (en) * | 2014-11-05 | 2015-03-11 | 贝兹维仪器(苏州)有限公司 | Power grid pole mud resistivity measurement system |
| CN107765091A (en) * | 2016-08-18 | 2018-03-06 | 国家电网公司 | A kind of original position soil sample resistance rate measurement apparatus |
| JP2018072052A (en) * | 2016-10-26 | 2018-05-10 | 株式会社クボタ | Specific resistance measuring apparatus of soil |
| CN206292307U (en) * | 2016-11-16 | 2017-06-30 | 李卓昊 | A kind of device of utilization Wheatstone bridge measuring resistance |
| CN208488497U (en) * | 2018-07-13 | 2019-02-12 | 飞鸣科学仪器（武汉）有限公司 | A kind of conductivity electrode |
| CN110118896A (en) * | 2018-11-13 | 2019-08-13 | 清华大学 | A kind of method and system measuring stratified soil resistivity and dielectric constant frequency dependent characteristic |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111141785A (en) | 2020-05-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111141785B (en) | Soil resistivity measuring device, method and storage medium | |
| CN109752663A (en) | A kind of measurement method of the internal resistance of cell | |
| CN201654130U (en) | Automatic measuring and calibrating device of high-impedance measuring apparatus | |
| KR100609713B1 (en) | Grounding resistance measurement and soil structure detection using the slope degree of voltage differences | |
| WO2022193454A1 (en) | Current sensor, current measurement device, system and apparatus, and storage medium | |
| CN106197607A (en) | A kind of device and method of accurate measurement level of ground water | |
| CN105891757A (en) | Open-loop Hall sensor measurement accuracy verification device and verification method thereof | |
| CN104750989A (en) | Single-core cable transient state thermal circuit model conductor temperature calculating method and device | |
| CN104407223A (en) | Combined resistivity measurement system and method for measuring resistivity by using combined resistivity measurement system | |
| So et al. | Intercomparison of calibration systems for AC shunts up to audio frequencies | |
| CN103424629B (en) | A kind of simple and easy method testing impedance of graphene oxide solution | |
| CN105372498A (en) | Shunt impedance parameter determining method for measuring transient current | |
| CN204347137U (en) | Combined resistance rate measuring system | |
| US7834641B1 (en) | Phase-gain calibration of impedance/admittance meter | |
| CN107589300A (en) | A kind of line impedance detection method, system, device and readable storage medium storing program for executing | |
| US20220341862A1 (en) | System and method for continuously and intelligently measuring water content of subgrade in real time | |
| CN103149472B (en) | Voltage-current mapping constructing method based on double-terminal excitation measuring model | |
| CN207408489U (en) | Circuit board detection equipment | |
| Fortuné et al. | Measurement method of AC current up to 1 MHz | |
| CN204631237U (en) | A kind of measurement detection system of digital earth resistance tester | |
| CN204495909U (en) | Wide-range high-accuracy electrical resistance collection circuit | |
| CN215866479U (en) | Probe and testing device for testing indirect electric resistance between silver paste and substrate | |
| CN108627787B (en) | Standard closed-loop resistor | |
| CN109358234A (en) | A kind of pole piece resistance conductivity test method | |
| CN108445290B (en) | Closed-loop resistor resistance value measuring method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |