CN101799284A - Wave monitoring plant for impending landslides - Google Patents

Wave monitoring plant for impending landslides Download PDF

Info

Publication number
CN101799284A
CN101799284A CN 201010127789 CN201010127789A CN101799284A CN 101799284 A CN101799284 A CN 101799284A CN 201010127789 CN201010127789 CN 201010127789 CN 201010127789 A CN201010127789 A CN 201010127789A CN 101799284 A CN101799284 A CN 101799284A
Authority
CN
China
Prior art keywords
circuit
impending
landslides
monitoring
pressure
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.)
Granted
Application number
CN 201010127789
Other languages
Chinese (zh)
Other versions
CN101799284B (en
Inventor
庹先国
余小平
冯怀升
王洪辉
穆克亮
杨剑波
李哲
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Chengdu Univeristy of Technology
Original Assignee
Chengdu Univeristy of Technology
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Chengdu Univeristy of Technology filed Critical Chengdu Univeristy of Technology
Priority to CN2010101277899A priority Critical patent/CN101799284B/en
Publication of CN101799284A publication Critical patent/CN101799284A/en
Application granted granted Critical
Publication of CN101799284B publication Critical patent/CN101799284B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The invention discloses a sound wave monitoring plant for landslide critical-slide, which comprises a pressure field sonic sensor, a monitoring host and a personal computer provided with landslide geologic hazard monitoring software, wherein the pressure field sonic sensor, the monitoring host and the personal computer provided with the landslide geologic hazard monitoring software are orderly connected; the monitoring host further processes a signal acquired by the pressure field sonic sensor; and the personal computer is used for storing, displaying, analyzing and prewarning the signal. The invention monitors the landslide by utilizing the sound wave information generated by rock rupture and friction when the sliding mass is in the impending state, can acquire predictive information before the sliding mass comes into the impending state and previously gives warning according to the software analysis, thereby reducing the loss of life and properties of people near the sliding mass due to the landslide.

Description

A kind of wave monitoring plant for impending landslides
Technical field
Sliding monitoring technical field is faced in the landslide that the present invention relates in the geologic hazard, particularly a kind of acoustic signals collection, and program control filtering, high-speed data is handled and transmission, and the wave monitoring plant for impending landslides of sliding expert decision-making early warning is faced on the landslide.
Background technology
The landslide is China's the most extensive and common geologic hazard that distributes, be characterized in sudden by force and endanger huge.The landslide dynamic monitoring has become the important means of preventing and reducing natural disasters.
For the Regional survey and the dynamic monitoring work of Regional Landslide, traditional approach and the means of obtaining the landslide status information mainly are, obtain the status information on non-emphasis landslide by mass presdiction and disaster prevention, obtain the status information on emphasis landslide with the routine monitoring means.Routine monitoring means such as displacement monitoring mainly contain relative displacement monitoring, absolute displacement monitoring (the earth distortion measurement), the monitoring of gliding mass deep displacement (borehole inclinometer monitoring), the monitoring of lateral aperture multi-point displacement, the monitoring of three-dimensional laser micrometric displacement etc.; Pressure monitoring; The groundwater environment monitoring; Simple and easy meteorological observation; Macroscopic view geological phenomenon investigation etc.Because Regional Landslide is in extensive range, the mass presdiction and disaster prevention method must expend great amount of manpower, and the routine monitoring means are because the monitoring means restriction is difficult in time obtain the tendency information that sliding mass faces sliding early stage, often be difficult to reach the effect of early warning, so classic method there is significant limitation.
Along with sensor technology, computer technology and development of internet technology, have at present that propose to use the 3S technology be that remote sensing technology (RS), Geographic Information System (GIS), GPS (GPS) are monitored the landslide, but many technical matterss wherein solve at all as yet; For example how directly to send the GPS Monitoring Data to generalized information system, realize that the tracking of landslide displacement and forecast do not have good solution at present.
Summary of the invention
At the problems referred to above, the invention discloses a kind of wave monitoring plant for impending landslides, this device utilizes sliding mass to face when sliding rock fracture and fricative information of acoustic wave to carry out landslide monitoring, can in time obtain the tendency information that sliding mass faces sliding early stage, and carry out early warning, thereby the loss that reduces to come down and bring near the people's life the sliding mass and property according to software analysis.
In order to achieve the above object, the technical solution used in the present invention is: a kind of wave monitoring plant for impending landslides, this device comprises pressure field sonic sensor, monitoring main frame and the PC of landslide geologic hazard monitoring of software has been installed, pressure field sonic sensor, monitoring main frame and the PC that geologic hazard monitoring of software in landslide has been installed are connected successively, the monitoring main frame is further handled the signal that the pressure field sonic sensor obtains, PC then be used for to signal store, show, analysis and early warning.
Wherein, the pressure field sonic sensor comprises pressure field microphone, adapter, prime amplifier, extended line, and its function is to finish sliding mass to face rock fracture and the collection of fricative information of acoustic wave and the pre-service of signal when sliding.
The monitoring main frame by every directly/impedance matching circuit, program control low-pass filter circuit, CPLD circuit, signal balancing and amplifying circuit, differential conversion circuit, SOC circuit, level shifting circuit, power circuit and high-pressure modular circuit form, finish the signal that the pressure field sonic sensor is obtained and further handle.
Wherein, block isolating circuit adopts electric capacity every directly, and electric capacity is the dielectric leaded multilayer ceramic capacitor of NPO;
Impedance matching circuit adopts the field effect cast amplifier TL082 with high input impedance, and adopts the homophase input;
Program control low-pass filter circuit adopts the switching capacity filter MAX263 of centre frequency, quality factor and mode of operation control able to programme to finish;
The operational amplifier of signal balancing and amplifying circuit is selected ICL7650CSA for use;
The differential conversion circuit adopts AD8138AR;
Level shifting circuit then is used for converting Transistor-Transistor Logic level to the RS-232C level.
The invention has the beneficial effects as follows: utilize sliding mass to face when sliding rock fracture and fricative information of acoustic wave and carry out landslide monitoring, can in time obtain the tendency information that sliding mass faces sliding early stage, and according to the software analysis early warning, thereby the loss that reduces to come down and bring near the people's life the sliding mass and property.
Description of drawings
Fig. 1 is a system architecture diagram of the present invention;
Fig. 2 is a pressure field sonic sensor structured flowchart;
Fig. 3 is monitoring main machine structure block diagram;
Fig. 4 be every directly/the impedance matching circuit circuit theory diagrams;
Fig. 5 is program control low-pass filter circuit circuit theory diagrams;
Fig. 6 is a CPLD circuit schematic diagram;
Fig. 7 is signal balancing and amplifying circuit circuit theory diagrams;
Fig. 8 is a differential conversion circuit schematic diagram;
Fig. 9 is a SOC circuit schematic diagram;
Figure 10 is the level shifting circuit circuit theory diagrams;
Figure 11 is the power circuit circuit theory diagrams;
Figure 12 is a high-pressure modular circuit schematic diagram.
Embodiment
For the easier quilt of the present invention is understood, the present invention is done being described in more detail below in conjunction with the drawings and specific embodiments.
Consult Fig. 1, a kind of wave monitoring plant for impending landslides, this device is made up of pressure field sonic sensor, monitoring main frame and PC that geologic hazard monitoring of software in landslide has been installed, utilizes sliding mass to face when sliding that rock ruptures and fricative information of acoustic wave carries out landslide monitoring and early warning; Wherein the pressure field sonic sensor is used to obtain signal, and the monitoring main frame is used for the signal that the pressure field sonic sensor obtains is further handled, and PC then is used to finish storage, demonstration, analysis and the early warning of signal.
Consult Fig. 2, the pressure field sonic sensor is made up of pressure field microphone, adapter, prime amplifier, extended line.In order to satisfy the measurement requirement that the acoustic signals that produces in the rock-soil material deformation fracture process when sliding is faced in the landslide, the pressure field sonic sensor is chosen Denmark B﹠amp; The pressure field sonic sensor of K company, model are 4193 types; The adapter model is UC-0211; Prime amplifier is 2669L; Extended line is the LEMO extended line.
Consult Fig. 3, the monitoring main frame by every directly/impedance matching circuit, program control low-pass filter circuit, CPLD circuit, signal balancing and amplifying circuit, differential conversion circuit, SOC circuit, level shifting circuit, power circuit and high-pressure modular circuit form.The monitoring main frame is finished the further processing of the signal that the pressure field sonic sensor is obtained: every straight, coupling, filtering, amplification, differential conversion, analog to digital conversion, transmission.
Consult Fig. 4, every directly/impedance matching circuit.The signal of pressure field sonic sensor output has the direct current biasing of 24V, and the operating voltage of signal processing circuit is ± 5V, therefore must carry out removing direct current biasing every directly to this signal.Here adopt electric capacity every directly, electric capacity is selected the dielectric leaded multilayer ceramic capacitor of NPO for use.The leaded multilayer ceramic capacitor electric property is stable, does not change with the change of temperature, voltage, time basically.Dc offset voltage is 24V, according to the derating designing requirement, the withstand voltage of leaded multilayer ceramic capacitor should be elected 48V as at least, according to capacity standard series, chosen the withstand voltage leaded multilayer ceramic capacitor of 63V that is, the leaded multilayer ceramic capacitor max cap. of 63V is 4.7uF, is the increase capacity, adopt 5 leaded multilayer ceramic capacitor C23, C24, C25, C26, C27 parallel connection during design, then the capacity increase is 5*4.7uF=23.5uF; By resistance R 15 signal is sent into the in-phase end of amplifier TL082 then.
Consult Fig. 4, for the signal that guarantees the output of pressure field sonic sensor passes to the signal processing circuit of monitoring main frame effectively, make its decay minimum, adopt field effect cast amplifier TL082 to design impedance matching circuit with high input impedance, and adopt the homophase input, to improve input impedance.
Consult Fig. 5, program control low-pass filter circuit is finished choosing of signal.Sliding mass faces the sliding frequency of sound wave that produces and concentrates in infrasonic sound and the common sound wave scope, and infrasonic sound (being lower than the signal of 20Hz) composition is more, therefore filtering circuit is arranged to low-pass filtering.Program control low-pass filter circuit adopts the switching capacity filter MAX263 of centre frequency, quality factor and mode of operation control able to programme to finish.Impedance matching circuit is finished the impedance matching between program control low-pass filter circuit and the follow-up signal amplification circuit, adopts the field effect cast amplifier TL082 with high input impedance to design impedance matching circuit, and adopts the homophase input, to improve input impedance.
Consult Fig. 6, the CPLD circuit.The clock of program control low-pass filter is provided by the CPLD circuit.Only need use 12 d type flip flops and 12 phase inverters with CPLD circuit design clock, and a clock input I/O mouth and 12 clock output I/O mouths, therefore select for use EPM7032SLC44 to meet design requirement.Change the centre frequency of programmable filter by the input clock that changes programmable filter.
Consult Fig. 7, signal balancing and amplifying circuit.Acoustic signals has 2 times gain through after the filtering of program control low-pass filter, phase phasic difference 180 degree.Block isolating circuit does not all remove all DC voltage, and the signal balancing circuit will all remove DC voltage.Regulator potentiometer RP2 can remove DC voltage.Simultaneously signal amplitude is further amplified, and anti-phase.The operational amplifier of signal balancing and amplifying circuit is selected ICL7650CSA for use.
Consult Fig. 8, the differential conversion circuit converts single-ended signal to differential signal.The differential conversion circuit adopts AD8138AR to finish.It is 0.1% 500 Ω precision resistances that resistance R 40 in the differential conversion circuit, R41, R42, R43 are precision.The center voltage of differential voltage is 1.65V, is obtained by two 10K Ω resistance R 37 and R38 dividing potential drop by the vdd voltage of 3.3V.
Consult Fig. 9, the SOC circuit is the core of monitoring main frame.The microprocessor of SOC circuit is selected high speed microprocessor C8051F340 for use, and C8051F340 inside carries 10 successive approximation register type ADC that sampling rate is 200ksps, can be directly used in the analog to digital conversion of signal.The acoustic signals frequency that the landslide produces when facing rock mass stress deformation when sliding or fracture belongs to low-frequency range, and according to Nyquist (Nyquist) sampling thheorem as can be known, this ADC can satisfy the analog to digital conversion requirement of this acoustic signals fully.
Consult Fig. 9, the P4.3 of C8051F340 and P4.4 are the analog difference signal input port, and P4.3 is a difference input anode, and P4.4 is a difference input negative terminal.C2D and RST/C2CK are that software debugging and program are downloaded private port.P2.0~P2.7 and P3.0~P3.5 make digital I/O mouth, are respectively applied for two parameters (quality factor Q and centre frequency) of configuration programmable filter MAX263.P0.4 and P0.5 make serial communication and use.VBUS, D+, D-and one digitally use as USB interface.The reference voltage of 10 ADC in the C8051F340 sheet is selected inner 3.3V voltage for use, and uses timer internal 2 regularly to overflow interruption and do the control of ADC sample frequency.The C8051F340 clock is obtained by the oscillatory circuit of C8051F340 inside, and clock setting is 12MHz, satisfies sensor sample and message transmission rate requirement fully.Reset circuit adopts the watchdog reset circuit of C8051F340 inside.
Consult Figure 10, level shifting circuit converts Transistor-Transistor Logic level to the RS-232C level.The level of RS-232C adopts negative logic, and promptly logical zero is :+5V~+ 15V, logical one is :-5V~-15V.Therefore, the PC serial ports of RS-232C level can not directly link to each other with the monitoring serial port of host computer of Transistor-Transistor Logic level, must carry out level conversion during use.
Consult Figure 11, power circuit is by U1 (being the AC-DC module), U2 (being the DC-DC module) and simulation ± 5V and numeral+5V power supply, and the simulation 3.3V of microprocessor and digital 3.3V power supply formation.
Consult U1 among Figure 11, the AC-DC module has been selected the wide region load module, and input voltage range is nominally 220V for exchanging 165~265V.Install total power consumption and be no more than 5W,, chosen the AC-DC module of 10W according to the derating designing requirement.The DC voltage of AC-DC module output is 48V, and the maximum current of output is 208mA, and the conversion efficiency representative value is greater than 80%, and input and the high isolation of output, has overcurrent, overheated, short-circuit protection, and self-recovering function.
Consult U2 among Figure 11, the DC-DC module has been selected the wide region load module, and input voltage range is direct current 36~72V, is nominally 48V.Inserted at input end and to have removed ripple capacitor C 1 and decoupling capacitor C2, can reduce the ripple input effectively and eliminate self-excitation.(± 5V) maximum current is 500mA, and the conversion efficiency representative value is greater than 80%, and input and the high isolation of output, has long-term short-circuit protection and self-recovering function for two-way output.
Consult Figure 11,, do not disturb mutually, guarantee each several part circuit reliability service, designed multi-group power: simulation ± 5V, numeral+5V, simulation 3.3V and digital 3.3V voltage for guaranteeing the mutual isolation of analog power and digital power.
Consult Figure 12, the high-pressure modular circuit.The pressure field sonic sensor needs the 200V dc polarization voltage, and polarizing voltage is lower to current requirements, adopts the boost module of 5V to 1000V to finish, and the electric current of boost module is elected 1mA as.The Adjustable Output Voltage of boost module.Resistance R 14 and adjustable resistance RP1 series connection, being used to regulate the boost module output voltage is 200V.200V voltage output end parallel connection among Figure 12 high pressure ceramic disc capacitor 103/1KV, can eliminate high frequency interference, guarantee that boost module works reliably and with long-term.0 Ohmage R7 among Figure 12, R8, R9 are mainly used in isolation, remove high frequency interference.
Geologic hazard monitoring of software in landslide comprises monitoring information processing, Man Machine Interface and data base administration three parts.Monitoring information is handled and promptly to be stored, shows, analysis and early warning.Man Machine Interface with Real-time and Dynamic graphic presentation, faces the information of acoustic wave that when sliding produce so that understand monitored sliding mass more intuitively with the data that receive.The data of all records are sorted out in data base administration, and are for future reference.C# exploitation, beautiful interface, easy operating are adopted in Real-time and Dynamic graphic presentation interface.

Claims (10)

1. wave monitoring plant for impending landslides, it is characterized in that: this device comprises pressure field sonic sensor, monitoring main frame and the PC of landslide geologic hazard monitoring of software has been installed, pressure field sonic sensor, monitoring main frame and the PC that geologic hazard monitoring of software in landslide has been installed are connected successively, the monitoring main frame is further handled the signal that the pressure field sonic sensor obtains, PC then be used for to signal store, show, analysis and early warning.
2. according to the described a kind of wave monitoring plant for impending landslides of claim 1, it is characterized in that: described signal is further handled and is comprised every straight, coupling, filtering, amplification, differential conversion, analog to digital conversion, transmission.
3. according to the described a kind of wave monitoring plant for impending landslides of claim 1, it is characterized in that: described pressure field sonic sensor comprises pressure field microphone, adapter, prime amplifier, extended line.
4. according to the described a kind of wave monitoring plant for impending landslides of claim 1, it is characterized in that: the monitoring main frame comprise every directly/impedance matching circuit, program control low-pass filter circuit, CPLD circuit, signal balancing and amplifying circuit, differential conversion circuit, SOC circuit, level shifting circuit, power circuit and high-pressure modular circuit.
5. according to the described a kind of wave monitoring plant for impending landslides of claim 4, it is characterized in that: described block isolating circuit adopts electric capacity every directly, and electric capacity is the dielectric leaded multilayer ceramic capacitor of NPO.
6. according to the described a kind of wave monitoring plant for impending landslides of claim 4, it is characterized in that: described impedance matching circuit adopts the field effect cast amplifier TL082 with high input impedance, and adopts the homophase input.
7. according to the described a kind of wave monitoring plant for impending landslides of claim 4, it is characterized in that: described program control low-pass filter circuit adopts the switching capacity filter MAX263 of centre frequency, quality factor and mode of operation control able to programme to finish.
8. according to the described a kind of wave monitoring plant for impending landslides of claim 4, it is characterized in that: the operational amplifier of described signal balancing and amplifying circuit is selected ICL7650CSA for use.
9. according to the described a kind of wave monitoring plant for impending landslides of claim 4, it is characterized in that: described differential conversion circuit adopts AD8138AR.
10. according to the described a kind of wave monitoring plant for impending landslides of claim 4, it is characterized in that: level shifting circuit is used for converting Transistor-Transistor Logic level to the RS-232C level.
CN2010101277899A 2010-03-19 2010-03-19 Wave monitoring plant for impending landslides Expired - Fee Related CN101799284B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2010101277899A CN101799284B (en) 2010-03-19 2010-03-19 Wave monitoring plant for impending landslides

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2010101277899A CN101799284B (en) 2010-03-19 2010-03-19 Wave monitoring plant for impending landslides

Publications (2)

Publication Number Publication Date
CN101799284A true CN101799284A (en) 2010-08-11
CN101799284B CN101799284B (en) 2012-05-02

Family

ID=42595066

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2010101277899A Expired - Fee Related CN101799284B (en) 2010-03-19 2010-03-19 Wave monitoring plant for impending landslides

Country Status (1)

Country Link
CN (1) CN101799284B (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102183781A (en) * 2011-01-14 2011-09-14 深圳思量微系统有限公司 Mountain landslide supervision method
CN102426391A (en) * 2011-09-05 2012-04-25 华南理工大学 Method for determining whether there is collision during robot operation
CN103177532A (en) * 2013-03-08 2013-06-26 山东理工大学 Remote roadbed landslide monitoring method and remote roadbed landslide monitoring device
CN104949635A (en) * 2014-03-27 2015-09-30 江西飞尚科技有限公司 Supersonic bridge dynamic deflection detector
CN106646589A (en) * 2016-10-18 2017-05-10 上海建工集团股份有限公司 Sound-wave-principle based large-scale slope body detection device and detection method thereof
CN107063881A (en) * 2017-05-08 2017-08-18 中国科学院、水利部成都山地灾害与环境研究所 A kind of landslide monitoring model equipment and its test method based on secondary audio technology
CN111336958A (en) * 2020-02-25 2020-06-26 广东瀚阳轨道信息科技有限公司 Side slope early warning system and method based on sound waves

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09274023A (en) * 1996-04-05 1997-10-21 Nec Corp Prediction system for landslide
CN101498598A (en) * 2009-03-10 2009-08-05 珠海市德莱环保科技有限公司 Wireless security monitoring system for large dam

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09274023A (en) * 1996-04-05 1997-10-21 Nec Corp Prediction system for landslide
CN101498598A (en) * 2009-03-10 2009-08-05 珠海市德莱环保科技有限公司 Wireless security monitoring system for large dam

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
《山地学报》 20070228 程谦恭等 高速远程崩滑动力学的研究现状及发展趋势 , 第01期 2 *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102183781A (en) * 2011-01-14 2011-09-14 深圳思量微系统有限公司 Mountain landslide supervision method
CN102426391A (en) * 2011-09-05 2012-04-25 华南理工大学 Method for determining whether there is collision during robot operation
CN102426391B (en) * 2011-09-05 2014-06-11 华南理工大学 Method for determining whether there is collision during robot operation
CN103177532A (en) * 2013-03-08 2013-06-26 山东理工大学 Remote roadbed landslide monitoring method and remote roadbed landslide monitoring device
CN103177532B (en) * 2013-03-08 2015-08-26 山东理工大学 A kind of Subgrade Landslide remote monitoring method and device
CN104949635A (en) * 2014-03-27 2015-09-30 江西飞尚科技有限公司 Supersonic bridge dynamic deflection detector
CN106646589A (en) * 2016-10-18 2017-05-10 上海建工集团股份有限公司 Sound-wave-principle based large-scale slope body detection device and detection method thereof
CN107063881A (en) * 2017-05-08 2017-08-18 中国科学院、水利部成都山地灾害与环境研究所 A kind of landslide monitoring model equipment and its test method based on secondary audio technology
CN107063881B (en) * 2017-05-08 2019-05-10 中国科学院、水利部成都山地灾害与环境研究所 A kind of landslide monitoring model equipment and its test method based on secondary audio technology
CN111336958A (en) * 2020-02-25 2020-06-26 广东瀚阳轨道信息科技有限公司 Side slope early warning system and method based on sound waves

Also Published As

Publication number Publication date
CN101799284B (en) 2012-05-02

Similar Documents

Publication Publication Date Title
CN101799284B (en) Wave monitoring plant for impending landslides
CN205544597U (en) Multi -functional three -phase power monitoring device
CN102759675B (en) On-line electric energy quality monitoring device
CN205210069U (en) Water quality monitoring system based on cloud
CN201673236U (en) Insulation live testing device for generator bearing
CN105590438A (en) Wireless data collection system based on remote control and data compression
CN204256037U (en) External overvoltage intelligent monitor system in a kind of 110kV transformer station
CN205594116U (en) Embedded industrial computer small current neutral grounding route selection device
CN204495374U (en) Full-automatic synchronous data sampling instrument
CN204694753U (en) A kind of high-precision transmission line of electricity electric current on-Line Monitor Device
CN203444241U (en) Printer allowing visible carbon powder remaining quantity
CN203706409U (en) Data acquisition and remote transmission equipment applied to multiple external interfaces
CN201867240U (en) Vibration recording instrument
CN205176134U (en) Join in marriage net harmonic monitoring facilities
CN205015419U (en) High -low voltage power distribution cabinet electric energy quality detection optimization structure
CN204945717U (en) The aobvious remote control terminal of a kind of local collection
CN204359842U (en) A kind of computer based cable data tester
CN203931170U (en) A kind of Intelligent infrared linear pressure write by hand device
CN204101630U (en) A kind of multiloop AC ammeter
CN208109927U (en) A kind of electrical equipment malfunction data logging plant
CN203065576U (en) Device for remotely monitoring cathode protection of crude oil long-distance pipeline
CN203367961U (en) Three-phase power supply protection recorder with fault recording function
CN201463875U (en) Deformation lifting monitoring instrument
CN203881916U (en) Electrical energy quality monitoring recorder for railway signal power source
CN202350811U (en) Parameter display circuit for self-traveling cotton picker

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20120502

Termination date: 20180319