CN204731324U - A kind of optical fiber high voltage electromagnetic field measuring sonde - Google Patents
A kind of optical fiber high voltage electromagnetic field measuring sonde Download PDFInfo
- Publication number
- CN204731324U CN204731324U CN201520422844.5U CN201520422844U CN204731324U CN 204731324 U CN204731324 U CN 204731324U CN 201520422844 U CN201520422844 U CN 201520422844U CN 204731324 U CN204731324 U CN 204731324U
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- module
- processing module
- operational amplifier
- high voltage
- 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
- 239000013307 optical fiber Substances 0.000 title claims abstract description 40
- 230000005672 electromagnetic field Effects 0.000 title claims abstract description 24
- 238000012545 processing Methods 0.000 claims abstract description 29
- 238000006243 chemical reaction Methods 0.000 claims abstract description 19
- 238000007781 pre-processing Methods 0.000 claims abstract description 12
- 239000003990 capacitor Substances 0.000 claims description 13
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 10
- 230000003321 amplification Effects 0.000 claims description 9
- 238000002955 isolation Methods 0.000 claims description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 6
- 229910052802 copper Inorganic materials 0.000 claims description 6
- 239000010949 copper Substances 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 4
- 230000002093 peripheral effect Effects 0.000 claims description 3
- 230000005684 electric field Effects 0.000 abstract description 44
- 238000005259 measurement Methods 0.000 abstract description 10
- 239000000523 sample Substances 0.000 abstract description 8
- 230000005540 biological transmission Effects 0.000 abstract description 6
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 238000000691 measurement method Methods 0.000 abstract description 4
- 238000010276 construction Methods 0.000 abstract description 3
- 230000006698 induction Effects 0.000 abstract description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000009434 installation Methods 0.000 abstract description 2
- 238000012360 testing method Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 6
- 238000009826 distribution Methods 0.000 description 5
- 238000011160 research Methods 0.000 description 5
- 238000001514 detection method Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 230000005693 optoelectronics Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000004020 conductor Substances 0.000 description 1
- 238000013480 data collection Methods 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 230000002463 transducing effect Effects 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Arrangements For Transmission Of Measured Signals (AREA)
Abstract
The utility model discloses a kind of optical fiber high voltage electromagnetic field measuring sonde, it is characterized in that, comprise potential electrode, the signal pre-processing module connected successively, A/D conversion and data processing module, transmitter module and optical fiber.The beneficial effect that the utility model reaches: 1. measure power frequency electric field by electric charge induction electric field measurement method, electric field measurement value adopts digitizing, and by Optical Fiber Transmission, and electric field probe adopts spherical enclosed construction, therefore antijamming capability is extremely strong; 2. working stability, volume can be very little, little on surrounding electric field impact, is easy to carry and installation, works alone, be affected by the external environment little; 3. relative to the expensive price of current electric field measurement instrument, the utility model cost of manufacture is lower, can apply in electric system in enormous quantities, for electromagnetic environment test, has a good application prospect and usable range widely.
Description
Technical field
The utility model relates to a kind of optical fiber high voltage electromagnetic field measuring sonde, belongs to distribution network technology field.
Background technology
Accurately measure power equipment surrounding space electric field and change in electric system, to power equipment manufacture and design and safe operation has important meaning, the insulation system optimization of such as high voltage electric power equip ment, the monitoring running state etc. of high-tension apparatus and electric system; Further, along with the raising of electric pressure, not only the Electric Field Distribution of power transmission and transforming equipment itself becomes the focus of research, and Power System Electromagnetic Compatibility problem also attracts people's attention, and studying it also needs electric field to detect.Except Power System Electromagnetic Compatibility problem, much also there is electromagnetic compatibility problem in other field, all needs the detection of power frequency electric field to support as its experiment.
Existing detection technique mainly contains optical principle and electrical principles electric field measurement method.The advantages such as optical principle mensuration has good insulation preformance, fast response time, security is high, volume is little and lightweight, but this kind of electric-field sensor is often expensive, when applying now, many problems are also had to need to overcome, such as, because electrooptical effect itself has temperature dependency, therefore generally there is the problem of temperature drift based on the electric field measurement method of electrooptical effect; When electro-optic crystal is in induced static or ELF (Extremely Low Frequency) electric field, will the change of charge shift and Electric Field Distribution be produced in body, cause the problem inputting transducing signal instability; The existence of space free electric charge and gathering at sensing plane of crystal in tested electric field, also can affect the distribution of crystal internal electric field.
Electrical principles is utilized to carry out the method mainly electric charge induction method of power frequency electric field detection at present, its ultimate principle is: the conductor sensor surface be in electric field can produce induced charge, for the needs measuring different frequency electric field, design corresponding sensor construction and sample circuit, induced charge is converted to the curtage signal having certain corresponding relation with electric field intensity to be measured, then signal is analyzed thus obtains electric field intensity.From the beginning of the seventies in last century, both at home and abroad the research of charge inductive type electric-field sensor is just risen.Stuttgart University, Germany was in 1984, original ball sensor is improved, devise and carry out data transmission and the two-dimentional ball-type electric field instrument of isolated high-voltage with optical fiber, its probe diameter is 4cm, maximum detection field intensity is 10kV/cm, it is 0.5kV/cm that most I surveys field intensity, and Measurement bandwidth reaches 10MHz; NBS analyzes the principle and errors that one dimension ball sensor is measured in uniform electric field and inhomogeneous field, and proved by actual measurement, measuring accuracy and the ball-type of the electric field instrument of flat shape plate structure, box-like are very close, can meet the General Requirements that power frequency electric field is measured.The domestic PMM8053A electromagnetic field measurements instrument being usually used in measurement electromagnetic field at present, the relative error that its EHP-50C pops one's head in when 50Hz, 1kV/m is ± 0.5dB, has very high accuracy.Studies in China from the eighties in last century progressively, Xi'an Communications University is at the ball-type electric field instrument of 2.5cm diameter of design in 1985, and in the survey field strength range of 0.11 ~ 10kV/cm, error is no more than 2%, within 2002, devises two dimensional electric field measuring instrument further again; North China Electric Power University 1993, nineteen ninety-five also carried out similar research, the diameter of development in 2004 is the ball-type electric field instrument of 6.25cm, can survey field strength range and bring up to 10 ~ 100kV/m further.Also have many units to be also engaged in correlative study as Fudan University, Ministry of Water Resources and Power Industry's DianKeYuan, China National Measuring Science Research Inst. etc., have accumulated rich experience and knowledge.
But, existing product is used for the measurement of high frequency analog signals, interference free performance is poor, expensive, be difficult to promote the use of, therefore research cost lower, handled easily, safe and reliable digitizing line-frequency electric field measuring device, can help around power department at-once monitor high voltage substation, transmission line of electricity and the Electric Field Distribution situation of inside switch cabinet, and the safety coefficient improving electrical production is significant.
Utility model content
For solving the deficiencies in the prior art, the purpose of this utility model is to provide a kind of optical fiber high voltage electromagnetic field measuring sonde, has low cost of manufacture, easy to operate, antijamming capability strong and use the advantages such as flexible.
In order to realize above-mentioned target, the utility model adopts following technical scheme:
A kind of optical fiber high voltage electromagnetic field measuring sonde, is characterized in that, comprises potential electrode, the signal pre-processing module connected successively, A/D conversion and data processing module, transmitter module and optical fiber; Described potential electrode comprises pcb board and two copper hemispherical Shells; Described pcb board is arranged between two copper hemispherical Shells; Described signal pre-processing module comprises the sample circuit module, pre-amplification circuit module, filter circuit module and the RMS-DC converter circuit module that connect successively; Described A/D conversion comprises with data processing module the A/D modular converter and data processing module that are connected successively; Described RMS-DC converter circuit module is connected with A/D modular converter, and data processing module is connected with transmitter module; Described signal pre-processing module, A/D conversion and data processing module and transmitter module are all arranged on pcb board.
Aforesaid a kind of optical fiber high voltage electromagnetic field measuring sonde, is characterized in that, also comprise power module, reset switch and charging inlet; Described power module is powered respectively to a number pretreatment module, A/D conversion and data processing module and transmitter module.
Aforesaid a kind of optical fiber high voltage electromagnetic field measuring sonde, is characterized in that, described pre-amplification circuit module and filter circuit module composition Butterworth second order active bandwidth-limited circuit.
Aforesaid a kind of optical fiber high voltage electromagnetic field measuring sonde, is characterized in that, described pre-amplification circuit module comprises the first operational amplifier, the first amplifier resistance, filter capacitor, the first stake resistance and direct earth capacitance; One end of described filter capacitor is as filter input, and the other end accesses the in-phase input end of the first operational amplifier; One end of described direct earth capacitance is connected with filter capacitor one end as filter input, other end ground connection; One end of described first amplifier resistance is connected with the common junction of direct earth capacitance, filter capacitor, and the other end accesses the input end of the first operational amplifier; One end of described first stake resistance is connected with the in-phase input end of the first operational amplifier, other end ground connection; The inverting input of described first operational amplifier is connected with self output terminal.
Aforesaid a kind of optical fiber high voltage electromagnetic field measuring sonde, is characterized in that, described filtering circuit comprises the second operational amplifier, the second amplifier resistance, isolation resistance and the second stake resistance; The inverting input of described second operational amplifier is connected by the output terminal of isolation resistance with the first operational amplifier; Described second amplifier resistant series is between the inverting input and output terminal of the second operational amplifier; The in-phase input end of described second operational amplifier is by the second ground resistance earth; The output terminal of described second operational amplifier is connected with the input end of data processing module by output resistance.
Aforesaid a kind of optical fiber high voltage electromagnetic field measuring sonde, it is characterized in that, described RMS-DC converter circuit module comprises RMS conversion chip and peripheral circuit.
Aforesaid a kind of optical fiber high voltage electromagnetic field measuring sonde, it is characterized in that, the electric pulse digital signal that data processing module transmits by described transmitter module converts light pulse digital signal to, and is drawn by described optical fiber.
Aforesaid a kind of optical fiber high voltage electromagnetic field measuring sonde, is characterized in that, described optical fiber adopts multimode optical fiber.
The beneficial effect that the utility model reaches: 1. measure power frequency electric field by electric charge induction electric field measurement method, electric field measurement value adopts digitizing, and by Optical Fiber Transmission, and electric field probe adopts spherical enclosed construction, therefore antijamming capability is extremely strong; 2. working stability, volume can be very little, little on surrounding electric field impact, is easy to carry and installation, works alone, be affected by the external environment little; 3. relative to the expensive price of current electric field measurement instrument, the utility model cost of manufacture is lower, can apply in electric system in enormous quantities, for electromagnetic environment test, has a good application prospect and usable range widely.
Accompanying drawing explanation
Fig. 1 is each unit connection diagram of the present utility model;
Fig. 2 is the circuit connection diagram of pre-amplification circuit;
Fig. 3 is the circuit connection diagram of filtering circuit;
Fig. 4 is the circuit connection diagram of RMS-DC converter circuit;
Fig. 5 is the connection diagram of transmitter unit;
Fig. 6 is utility model works process flow diagram.
The implication of Reference numeral in figure:
1-potential electrode, 2-signal pre-processing module, 3-A/D changes and data processing module, 4-transmitter module, 5-power module, 6-optical fiber, 7-reset switch, 8-charging inlet, U1-first operational amplifier, R15-first amplifier resistance, C40-filter capacitor, R16-first stake resistance, C15-direct earth capacitance, U2-second operational amplifier, R22-second amplifier resistance, R5-isolation resistance, R20-second stake resistance.
Embodiment
Below in conjunction with accompanying drawing, the utility model is further described.Following examples only for clearly the technical solution of the utility model being described, and can not limit protection domain of the present utility model with this.
A kind of optical fiber 6 high voltage electromagnetic field measuring sonde that the utility model relates to, comprises potential electrode 1, power module 5, reset switch 7, charging inlet 8, the signal pre-processing module 2 connected successively, A/D conversion and data processing module 3, transmitter module 4 and optical fiber 6.
As shown in Figure 1, signal pre-processing module 2 comprises the sample circuit module, pre-amplification circuit module, filter circuit module and the RMS-DC converter circuit module that connect successively.A/D conversion comprises with data processing module 3 the A/D modular converter and data processing module that are connected successively.RMS-DC converter circuit module is connected with A/D modular converter, and data processing module is connected with transmitter module 4.Power module 5 is powered respectively to a number pretreatment module, A/D conversion and data processing module 3 and transmitter module 4.
In the present embodiment, the processor that system adopts is C8051F020, and Embedded 12 is the A/D converting unit of sampling rate 200sps, can be converted to digital signal to the pretreated simulating signal of front end signal.The reference voltage of AD sampling is produced by processor inside programming, and size is 2.4V, can be signal reliable samples between 0-2.4V to amplitude.AD conversion unit has 8 acquisition channels, and system opens 1 passage for electric field data collection.According to general electric field measurement requirement, processor adopts timer timing sampling, and sample frequency is 1kHz, carries out average value processing to higher than the data in the power frequency period time, obtains accurate Electric Field Numerical.
Potential electrode 1 comprises pcb board and two copper hemispherical Shells, and pcb board is arranged between two copper hemispherical Shells.Signal pre-processing module 2, A/D conversion and data processing module 3 and transmitter module 4 are all arranged on pcb board.Sample circuit signal input part is connected to potential electrode 1, in the present embodiment, because singlechip chip is integrated with A/D converting unit, so the electric field intensity signal after pre-process circuit directly sends into single-chip microcomputer.
Pre-amplification circuit module and filter circuit module composition Butterworth second order active bandwidth-limited circuit.
As shown in Figure 2, pre-amplification circuit module comprises the first operational amplifier U1, the first amplifier resistance R15, filter capacitor C40, the first stake resistance R16 and direct earth capacitance C15.
Annexation is as follows: one end of filter capacitor C40 is as filter input, and the other end accesses the in-phase input end of the first operational amplifier U1.One end of direct earth capacitance C15 is connected as one end of filter input with filter capacitor C40, other end ground connection.One end of first amplifier resistance R15 is connected with the common junction of direct earth capacitance C15, filter capacitor C40, and the other end accesses the input end of the first operational amplifier U1.One end of first stake resistance R16 is connected with the in-phase input end of the first operational amplifier U1, other end ground connection.The inverting input of the first operational amplifier U1 is connected with self output terminal.
As shown in Figure 3, filtering circuit comprises the second operational amplifier U2, the second amplifier resistance R22, isolation resistance R5 and the second stake resistance R20.
Annexation is as follows: the inverting input of the second operational amplifier U2 is connected with the output terminal of the first operational amplifier U1 by isolation resistance R5.Between the inverting input that second amplifier resistance R22 is connected on the second operational amplifier U2 and output terminal.The in-phase input end of the second operational amplifier U2 is by the second stake resistance R20 ground connection.The output terminal of the second operational amplifier U2 is connected with the input end of data processing module by output resistance.
In the present embodiment, the first operational amplifier U1 and the second operational amplifier U2 all adopts OP07C.
As shown in Figure 4, RMS-DC converter circuit module comprises RMS conversion chip and peripheral circuit.Wherein, RMS conversion chip have employed AD637, the AC signal within 2v can be converted to direct current signal.
As shown in Figure 5, transmitter module 4 comprises the light drive circuit and optical connector that are connected with data processing unit, for real-time Transmission electric field data, wherein adopt LED in transmitter module 4, the electric pulse digital signal transmitted by data processing module converts light pulse digital signal to, and is drawn by optical fiber 6.Optical fiber 6 adopts multimode optical fiber 6.
As shown in Figure 6, workflow of the present utility model is as follows: after switch powers on, and system carries out initialization, and to each working cell module self-inspection.Then the A/D modular converter in single-chip microcomputer starts to carry out AD conversion to the voltage signal of signal pre-processing module 2; After terminating a change-over period, by single-chip microcomputer, analyzing and processing is carried out to the digital signal gathered, obtain the measured value of electric field intensity and be sent to receiving end by optical fiber 6.
The above is only preferred implementation of the present utility model; should be understood that; for those skilled in the art; under the prerequisite not departing from the utility model know-why; can also make some improvement and distortion, these improve and distortion also should be considered as protection domain of the present utility model.
Claims (8)
1. an optical fiber high voltage electromagnetic field measuring sonde, is characterized in that, comprises potential electrode, the signal pre-processing module connected successively, A/D conversion and data processing module, transmitter module and optical fiber; Described potential electrode comprises pcb board and two copper hemispherical Shells; Described pcb board is arranged between two copper hemispherical Shells; Described signal pre-processing module comprises the sample circuit module, pre-amplification circuit module, filter circuit module and the RMS-DC converter circuit module that connect successively; Described A/D conversion comprises with data processing module the A/D modular converter and data processing module that are connected successively; Described RMS-DC converter circuit module is connected with A/D modular converter, and data processing module is connected with transmitter module; Described signal pre-processing module, A/D conversion and data processing module and transmitter module are all arranged on pcb board.
2. a kind of optical fiber high voltage electromagnetic field measuring sonde according to claim 1, is characterized in that, also comprise power module, reset switch and charging inlet; Described power module is powered respectively to a number pretreatment module, A/D conversion and data processing module and transmitter module.
3. a kind of optical fiber high voltage electromagnetic field measuring sonde according to claim 1, is characterized in that, described pre-amplification circuit module and filter circuit module composition Butterworth second order active bandwidth-limited circuit.
4. a kind of optical fiber high voltage electromagnetic field measuring sonde according to claim 3, is characterized in that, described pre-amplification circuit module comprises the first operational amplifier, the first amplifier resistance, filter capacitor, the first stake resistance and direct earth capacitance; One end of described filter capacitor is as filter input, and the other end accesses the in-phase input end of the first operational amplifier; One end of described direct earth capacitance is connected with filter capacitor one end as filter input, other end ground connection; One end of described first amplifier resistance is connected with the common junction of direct earth capacitance, filter capacitor, and the other end accesses the input end of the first operational amplifier; One end of described first stake resistance is connected with the in-phase input end of the first operational amplifier, other end ground connection; The inverting input of described first operational amplifier is connected with self output terminal.
5. a kind of optical fiber high voltage electromagnetic field measuring sonde according to claim 4, is characterized in that, described filtering circuit comprises the second operational amplifier, the second amplifier resistance, isolation resistance and the second stake resistance; The inverting input of described second operational amplifier is connected by the output terminal of isolation resistance with the first operational amplifier; Described second amplifier resistant series is between the inverting input and output terminal of the second operational amplifier; The in-phase input end of described second operational amplifier is by the second ground resistance earth; The output terminal of described second operational amplifier is connected with the input end of data processing module by output resistance.
6. a kind of optical fiber high voltage electromagnetic field measuring sonde according to claim 1, it is characterized in that, described RMS-DC converter circuit module comprises RMS conversion chip and peripheral circuit.
7. a kind of optical fiber high voltage electromagnetic field measuring sonde according to claim 1, it is characterized in that, the electric pulse digital signal that data processing module transmits by described transmitter module converts light pulse digital signal to, and is drawn by described optical fiber.
8. a kind of optical fiber high voltage electromagnetic field measuring sonde according to claim 7, is characterized in that, described optical fiber adopts multimode optical fiber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520422844.5U CN204731324U (en) | 2015-06-18 | 2015-06-18 | A kind of optical fiber high voltage electromagnetic field measuring sonde |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520422844.5U CN204731324U (en) | 2015-06-18 | 2015-06-18 | A kind of optical fiber high voltage electromagnetic field measuring sonde |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN204731324U true CN204731324U (en) | 2015-10-28 |
Family
ID=54389662
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201520422844.5U Active CN204731324U (en) | 2015-06-18 | 2015-06-18 | A kind of optical fiber high voltage electromagnetic field measuring sonde |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN204731324U (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104950189A (en) * | 2015-06-18 | 2015-09-30 | 国家电网公司 | Measuring probe for optical fiber power-frequency high-voltage electric field |
| CN105572482A (en) * | 2015-12-18 | 2016-05-11 | 国网冀北电力有限公司张家口供电公司 | Enclosed space electric field measurement device |
| CN106199223A (en) * | 2016-09-13 | 2016-12-07 | 重庆大学 | A kind of portable electric field measurement sensor |
| CN108627708A (en) * | 2017-03-22 | 2018-10-09 | 中国电力科学研究院 | The implementation method of based on WLAN impact electric field measurement system |
-
2015
- 2015-06-18 CN CN201520422844.5U patent/CN204731324U/en active Active
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104950189A (en) * | 2015-06-18 | 2015-09-30 | 国家电网公司 | Measuring probe for optical fiber power-frequency high-voltage electric field |
| CN105572482A (en) * | 2015-12-18 | 2016-05-11 | 国网冀北电力有限公司张家口供电公司 | Enclosed space electric field measurement device |
| CN105572482B (en) * | 2015-12-18 | 2020-06-09 | 国网冀北电力有限公司张家口供电公司 | Closed space electric field measuring equipment |
| CN106199223A (en) * | 2016-09-13 | 2016-12-07 | 重庆大学 | A kind of portable electric field measurement sensor |
| CN108627708A (en) * | 2017-03-22 | 2018-10-09 | 中国电力科学研究院 | The implementation method of based on WLAN impact electric field measurement system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104950189A (en) | Measuring probe for optical fiber power-frequency high-voltage electric field | |
| CN201892707U (en) | Measuring system for electric field | |
| CN204731324U (en) | A kind of optical fiber high voltage electromagnetic field measuring sonde | |
| CN104569902B (en) | Digital type electric energy meter power consumption measuring device and method | |
| CN202974924U (en) | Online earth resistivity monitoring system | |
| CN204439822U (en) | A kind of electronic type voltage transformer on-line testing system | |
| CN204536448U (en) | A kind of high voltage supply leakage conductor wireless monitoring device | |
| CN205193212U (en) | Insulating detecting system of DC cable | |
| CN203722628U (en) | Power carrier channel communication tester | |
| CN103412185A (en) | Lightning current detecting device | |
| CN202676649U (en) | Capacitive sensor for synchronous real-time self-compensation measurement of soil moisture content | |
| CN102360042A (en) | All-weather power-frequency electric field measuring device | |
| CN103675483A (en) | All-weather power frequency electric field measuring device | |
| CN104777445B (en) | A kind of electronic type voltage transformer on-line testing system | |
| CN204462246U (en) | A kind of HVDC (High Voltage Direct Current) transmission line corona loss measuring system | |
| CN203551116U (en) | Device for collecting temperature of high-voltage overhead transmission line | |
| CN204964656U (en) | Portable insulator intellectual detection system appearance | |
| CN107328989B (en) | Transformer substation overvoltage monitoring system and method based on wireless acquisition technology | |
| CN204116451U (en) | A kind of Energy Efficiency of Distribution Transformer measuring and testing device | |
| CN201886067U (en) | Online voltage harmonic monitoring system for wind farms | |
| CN202794278U (en) | High-precision handheld type digital oscilloscope | |
| CN203705561U (en) | All-weather power-frequency electric field measuring device | |
| CN203858290U (en) | Wireless sensor for measuring end-screen current of capacitive equipment | |
| CN203084093U (en) | Monitor used for lightning arrester | |
| CN202975211U (en) | Photoelectric trigger device for transient disturbance test of transformer substation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |