CN108414112A - A kind of Discrete Production Workshop device temperature monitoring device and method based on Internet of Things - Google Patents
A kind of Discrete Production Workshop device temperature monitoring device and method based on Internet of Things Download PDFInfo
- Publication number
- CN108414112A CN108414112A CN201810128481.2A CN201810128481A CN108414112A CN 108414112 A CN108414112 A CN 108414112A CN 201810128481 A CN201810128481 A CN 201810128481A CN 108414112 A CN108414112 A CN 108414112A
- Authority
- CN
- China
- Prior art keywords
- signal
- fiber
- grating sensor
- coupler
- optic grating
- 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.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
- G01K11/3206—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres at discrete locations in the fibre, e.g. using Bragg scattering
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K1/00—Details of thermometers not specially adapted for particular types of thermometer
- G01K1/02—Means for indicating or recording specially adapted for thermometers
- G01K1/024—Means for indicating or recording specially adapted for thermometers for remote indication
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K1/00—Details of thermometers not specially adapted for particular types of thermometer
- G01K1/02—Means for indicating or recording specially adapted for thermometers
- G01K1/026—Means for indicating or recording specially adapted for thermometers arrangements for monitoring a plurality of temperatures, e.g. by multiplexing
Abstract
The Discrete Production Workshop equipment safety monitoring device based on Internet of Things that the invention discloses a kind of, which is characterized in that including：Laser, Polarization Controller, modulator, first erbium-doped fiber amplifier, circulator, first fiber-optic grating sensor, second fiber-optic grating sensor, third fiber-optic grating sensor, second erbium-doped fiber amplifier, first photo-coupler, filter, second coupler, photodetector, data acquisition card, Zigbee transmission module, ZigBee coordinators, signal processing and display unit, it can be transmitted reduction using wireless transmitting system and endanger performance, with relatively simple for structure, the workshop that long transmission distance is suitble to area larger, monitoring signals will not be by object in workshop blocking and interference and the effect that is easily achieved.
Description
Technical field
The present invention relates to safety monitoring fields, more particularly to a kind of Discrete Production Workshop device temperature based on Internet of Things
Monitoring device and method.
Background technology
With the fast development of China's economy, process of industrialization has obtained propulsion at full speed, however the safety brought therewith
But very severe, the frequent generation of all kinds of serious accidents not only cause personal injury to related practitioner, return state problem
Family causes huge economic loss and forms severe social influence, these accident parts are related to setting for processing workshop
It is standby detect, relevant issues such as monitoring in real time.In the workshop of modernization, since the large-scale instrument in workshop is in production process
In will appear fever variation caused by accident, cause huge economic loss to enterprise, therefore, develop various quick responses, height
Sensitivity, the workshop detecting system that can be remotely located detection are imperative, it has also become the main research of current field of sensing technologies
Content.In addition, plus the pollution of the noise and pernicious gas etc. occurred in manufacture process, certain wound is caused to human body
Evil, therefore, the workshop detection sensor system for studying wireless transmission are a kind of inexorable trends and in the urgent need to address at present ask
Topic.Researcher has done a large amount of theoretical and experimental study, achieves certain effect.But monitoring systems most uses at present
The transmission range of the mode of RF tag, which is smaller, is not suitable for the larger workshop of area, and the object in workshop is easy resistance
The transmission for keeping off signal, can not achieve the requirement monitored in real time.
Therefore, it is necessary to a kind of temperature informations that can accurately obtain Discrete Production Workshop equipment, can utilize wireless transmission
System is transmitted reduction and endangers performance, and relatively simple for structure, it is easy to accomplish temperature monitoring device and method.
ZigBee is the low-power consumption LAN protocol based on IEEE802.15.4 standards.Its main feature is that short distance, low complexity
Degree, self-organizing, low-power consumption, low data rate.It is mainly suitable for, for automatically controlling and remote control field, various set being embedded in
It is standby.
Invention content
The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide one kind to utilize wireless transmission
System is transmitted reduction and endangers performance, relatively simple for structure, and the workshop that long transmission distance is suitble to area larger, monitoring signals are not
Can by object in workshop blocking and interference, it is easy to accomplish based on Internet of Things Discrete Production Workshop device temperature monitoring dress
It sets and method.
In order to solve the above technical problems, the present invention provides a kind of Discrete Production Workshop equipment safety monitoring based on Internet of Things
Device, which is characterized in that including：Laser, Polarization Controller, modulator, the first erbium-doped fiber amplifier, circulator, first
Fiber-optic grating sensor, the second fiber-optic grating sensor, third fiber-optic grating sensor, the second erbium-doped fiber amplifier, first
Photo-coupler, filter, the second coupler, photodetector, data acquisition card, Zigbee transmission module, ZigBee coordinators,
The laser signal that signal processing and display unit, wherein laser are sent out enters modulator, pulse generation by Polarization Controller
The electric impulse signal that device is sent out drives modulator, modulator that laser signal is modulated into pulse-modulated signal, the impulse modulation
Signal is amplified into the ports 1# of circulator through the first erbium-doped fiber amplifier, leads to successively after the output of the ports 2# of circulator
The first fiber-optic grating sensor, the second fiber-optic grating sensor, third fiber-optic grating sensor are crossed, from the first optical fiber grating sensing
The signal with metrical information of device, the second fiber-optic grating sensor and the reflection of third fiber-optic grating sensor enters circulator
The ports 2#, and exported by the ports 3# of circulator, which is amplified into the first coupler through the second erbium-doped fiber amplifier,
The signal exported from the first coupler is divided into two paths of signals, and signal enters the second coupler all the way, and another way signal is filtered
Enter the second coupler after device filtering, the signal exported from the second coupler enters photodetector, and photodetector is input
Signal be converted into electric signal, which is input to data acquisition card, and data acquisition card synchronizes company with impulse generator
It connects, the output end connection ZigBee transmission modules of data acquisition card are wirelessly transferred, and are received by ZigBee coordinators above-mentioned
Wireless transmission signal, the signal received are compared processing through signal processing and display unit and show.
The laser is wideband light source, and the modulator is in electrooptic modulator, acousto-optic modulator, phase-modulator
It is a kind of.
The photodetector is balanced detector or the photodetector of other types, and the fiber-optic grating sensor is
It is one or more in polarization-maintaining fiber grating sensor, general single mode fiber grating sensor and micro-nano fiber grating sensor.
A kind of Discrete Production Workshop equipment safety monitoring method based on Internet of Things, includes the following steps：
The laser signal that laser is sent out is incident on modulator by Polarization Controller, the electricity sent out by impulse generator
Pulse signal drives modulator, modulator that laser signal is modulated into pulse-modulated signal, which passes through first
Erbium-doped fiber amplifier amplifies, and passes to the first fiber-optic grating sensor, the second fiber-optic grating sensor successively by circulator
With third fiber-optic grating sensor, then by circulator the signal with metrical information of reflection is exported to the second Er-doped fiber
Amplifier is amplified into the first coupler by the second erbium-doped fiber amplifier,
The signal of output is divided into the first beam signal and the second beam optical signal by the first coupler；
First beam signal is directly inputted to the second coupler, as with reference to signal；
Second beam signal is input to the second coupler by filter, as measured signal；
After the output signal wavelength of adjusting filter filters out noise signal, phase is carried out on the second coupler with reference signal
Dry-cured meat；
The signal that above-mentioned second coupler exports is input to photodetector, optical signal is converted into electricity by photodetector
Signal, and it is output to data acquisition card, data acquisition card is synchronized with impulse generator and is connect, and passes through the defeated of data acquisition card
Outlet is transferred to Zigbee transmission module, then is transmitted outward by ZigBee transmission modules；
ZigBee coordinators receive the signal that above-mentioned ZigBee transmission modules are sent out, by signal processing and display unit into
Row processing, the location information of fiber-optic grating sensor is calculated by the transmission time of pulse-modulated signal, when fiber grating passes
Sensor is affected by temperature, and the centre wavelength of reflection will change, and optical fiber grating sensing can be obtained according to variable quantity
The temperature information measured on device and display.
The advantageous effect that the present invention is reached:It can be transmitted reduction using wireless transmitting system and endanger performance, structure
Fairly simple, long transmission distance is suitble to the larger workshop of area, monitoring signals will not by the blocking and interference of object in workshop,
And it is easily achieved.
Description of the drawings
Fig. 1 is the structural schematic block diagram of exemplary embodiment of the present invention；
Fig. 2 is the waveform diagram of three fiber-optic grating sensors reflection signal in exemplary embodiment of the present invention；
Fig. 3 is that the relationship between fiber-optic grating sensor measurement distance and temperature in exemplary embodiment of the present invention is shown
It is intended to.
Specific implementation mode
The present invention is further illustrated with exemplary embodiment below in conjunction with the accompanying drawings：
As shown in Figure 1, laser 200 sends out the laser signal that power is 5dBm enters electric light by Polarization Controller 201
Modulator 202, electrooptic modulator 202 generate the pulse signal that pulsewidth is 200ns by impulse generator 213 and drive electrooptic modulator
202 incident laser signals are modulated into pulse-modulated signal, and pulse-modulated signal amplifies through the first erbium-doped fiber amplifier 203
Enter the first port of circulator 204 to the signal that power is 20dBm, the is output and then enter from the second port of circulator 204
One fiber-optic grating sensor 205 (centre wavelength 1529.9nm), herein, since workshop measured object is discrete, area is larger
Workshop in measured object interval farther out, and between each other be easy blocking or interference, so compare other sensors type, choosing
Select that fiber grating point sensor is even more ideal, the pulse-modulated signal exported from the first fiber-optic grating sensor 205 enters the
Two fiber-optic grating sensors 206 (centre wavelength 1530.8nm), the impulse modulation letter exported from the second fiber-optic grating sensor 206
Number enter third fiber-optic grating sensor 207 (centre wavelength 1531.9nm), from the first fiber-optic grating sensor 205, the second light
The signal with metrical information that fiber grating sensor 206 and third fiber-optic grating sensor 207 reflect enters circulator 204
Second port, three fiber-optic grating sensors are pasted onto using high-temperature-resistant adhesive on lathe, from the second port of circulator 204
It is exported into the reflection signal of circulator 204 from the third port of circulator 204, the signal is through the second erbium-doped fiber amplifier
208 are amplified into the first coupler 209, and the signal exported from the first coupler 209 is divided into two paths of signals, all the way as reference
Signal enters the second coupler 211, and another way enters the second coupler after being filtered as the filtered device 210 of measured signal
211, after measured signal wavelength filters out noise signal, Coherent coupling is carried out on the second coupler 211 with reference signal；From second
The signal that coupler 211 exports enters photodetector 212, and the signal of input is converted into electric signal by photodetector 212, should
Electric signal is input to data acquisition card 214, and data acquisition card 214 is synchronized with impulse generator 213 and connect, data acquisition card
214 output end connection ZigBee transmission modules 215 are wirelessly transferred, and are received above-mentioned signal by ZigBee coordinators 216, are connect
The signal received is compared processing through signal processing and display unit 217 and shows the temperature letter of each measured object in workshop
Breath.The reflection signal waveform of three fiber-optic grating sensors measured, as shown in Fig. 2, it can be seen from the figure that reflecting signal
Centre wavelength is respectively 1529.9nm, 1530.8nm and 1531.9nm, using determining temperature and wavelength at calibration method calibration in advance
Relationship, measure and obtain the temperature of three fiber-optic grating sensors and the relationship of distance as shown in figure 3, as can be seen from the figure three
The location information of a fiber-optic grating sensor is respectively 56m, 98m and 139m, and the temperature measured is respectively 43.5 DEG C, 42.5 DEG C
With 42.1 DEG C.
In conclusion the relationship of direct ratio is presented using the reflection kernel wavelength of fiber-optic grating sensor with temperature by the present invention,
The temperature characterisitic for obtaining Discrete Production Workshop testee, is transmitted by wireless transmitting system, may be located remotely from workshop in this way
The radiation of harmful substance improves monitoring efficiency to reduce the harm to human body, reduces the probability that workshop accident occurs.
Above example does not limit the present invention in any way, every to be made in a manner of equivalent transformation to above example
Other improvement and application, belong to protection scope of the present invention.
Claims (4)
1. a kind of Discrete Production Workshop equipment safety monitoring device based on Internet of Things, which is characterized in that including：Laser, partially
Shake controller, modulator, the first erbium-doped fiber amplifier, circulator, the first fiber-optic grating sensor, the second optical fiber grating sensing
Device, third fiber-optic grating sensor, the second erbium-doped fiber amplifier, the first photo-coupler, filter, the second coupler, photoelectricity
Detector, data acquisition card, Zigbee transmission module, ZigBee coordinators, signal processing and display unit, wherein laser are sent out
The laser signal gone out enters modulator by Polarization Controller, and the electric impulse signal that impulse generator is sent out drives modulator, adjusts
Laser signal is modulated into pulse-modulated signal by device processed, and the pulse-modulated signal amplifies laggard through the first erbium-doped fiber amplifier
The ports 1# for entering circulator pass sequentially through the first fiber-optic grating sensor, the second optical fiber light after the output of the ports 2# of circulator
Gate sensor, third fiber-optic grating sensor, from the first fiber-optic grating sensor, the second fiber-optic grating sensor and third optical fiber
The signal with metrical information of grating sensor reflection enters the ports 2# of circulator, and is exported by the ports 3# of circulator,
The signal is amplified into the first coupler through the second erbium-doped fiber amplifier, and the signal exported from the first coupler is divided into two-way
Signal, all the way signal enter the second coupler, enter the second coupler after the filtered device filtering of another way signal, from the second coupling
The signal of clutch output enters photodetector, and the signal of input is converted into electric signal by photodetector, electric signal input
To data acquisition card, data acquisition card is synchronized with impulse generator and is connect, and the output end of data acquisition card connects ZigBee
Transmission module is wirelessly transferred, and above-mentioned wireless transmission signal is received by ZigBee coordinators, and the signal received is through signal
Processing and display unit are compared processing and show.
2. a kind of Discrete Production Workshop equipment safety monitoring device based on Internet of Things according to claim 1, feature
It is, the laser is wideband light source, and the modulator is one in electrooptic modulator, acousto-optic modulator, phase-modulator
Kind.
3. a kind of Discrete Production Workshop equipment safety monitoring device based on Internet of Things according to claim 1, feature
It is, the photodetector is balanced detector or the photodetector of other types, and the fiber-optic grating sensor is to protect
It is one or more in polarisation fiber grating sensor, general single mode fiber grating sensor and micro-nano fiber grating sensor.
4. a kind of Discrete Production Workshop equipment safety monitoring method based on Internet of Things according to claim 1-3, special
Sign is, includes the following steps：
The laser signal that laser is sent out is incident on modulator by Polarization Controller, the electric pulse sent out by impulse generator
Signal drives modulator, modulator that laser signal is modulated into pulse-modulated signal, which passes through the first er-doped
Fiber amplifier amplifies, and passes to the first fiber-optic grating sensor, the second fiber-optic grating sensor and the successively by circulator
Three fiber-optic grating sensors, then exported the signal with metrical information of reflection to the second Erbium-doped fiber amplifier by circulator
Device is amplified into the first coupler by the second erbium-doped fiber amplifier,
The signal of output is divided into the first beam signal and the second beam optical signal by the first coupler；
First beam signal is directly inputted to the second coupler, as with reference to signal；
Second beam signal is input to the second coupler by filter, as measured signal；
After the output signal wavelength of adjusting filter filters out noise signal, relevant coupling is carried out on the second coupler with reference signal
It closes；
The signal that above-mentioned second coupler exports is input to photodetector, optical signal is converted into telecommunications by photodetector
Number, and it is output to data acquisition card, data acquisition card is synchronized with impulse generator and is connect, and passes through the output of data acquisition card
End is transferred to Zigbee transmission module, then is transmitted outward by ZigBee transmission modules；
ZigBee coordinators receive the signal that above-mentioned ZigBee transmission modules are sent out, at signal processing and display unit
Reason, the location information of fiber-optic grating sensor is calculated by the transmission time of pulse-modulated signal, works as fiber-optic grating sensor
Affected by temperature, the centre wavelength of reflection will change, and can be obtained on fiber-optic grating sensor according to variable quantity
The temperature information of measurement and display.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810128481.2A CN108414112A (en) | 2018-02-08 | 2018-02-08 | A kind of Discrete Production Workshop device temperature monitoring device and method based on Internet of Things |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810128481.2A CN108414112A (en) | 2018-02-08 | 2018-02-08 | A kind of Discrete Production Workshop device temperature monitoring device and method based on Internet of Things |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN108414112A true CN108414112A (en) | 2018-08-17 |
Family
ID=63128062
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810128481.2A Pending CN108414112A (en) | 2018-02-08 | 2018-02-08 | A kind of Discrete Production Workshop device temperature monitoring device and method based on Internet of Things |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108414112A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113804452A (en) * | 2021-07-30 | 2021-12-17 | 湖北三江航天万峰科技发展有限公司 | Distributed automobile fault monitoring system and method |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2440952A (en) * | 2006-08-16 | 2008-02-20 | Schlumberger Holdings | Measuring Brillouin backscatter from an optical fibre using digitisation |
| CN101825499A (en) * | 2010-05-18 | 2010-09-08 | 华北电力大学（保定） | Method for measuring sea water temperature profile based on optical fiber Brillouin scattering principle |
| CN103513147A (en) * | 2013-09-09 | 2014-01-15 | 华北电力大学（保定） | Submarine cable real-time monitoring system and submarine cable real-time monitoring method |
| JP2014167399A (en) * | 2013-02-28 | 2014-09-11 | Yokogawa Electric Corp | Optical fiber temperature distribution measuring device |
| CN105806465A (en) * | 2016-03-11 | 2016-07-27 | 南京大学 | Novel [phi]-OTDR detection device based on fixed reflection points and detection method thereof |
| CN106197741A (en) * | 2016-07-14 | 2016-12-07 | 盐城工学院 | Temperature-detecting device based on micro-nano long-period fiber grating sensor and method |
| CN106225907A (en) * | 2016-06-28 | 2016-12-14 | 浙江大学 | A kind of fiber-optic vibration identification system and method based on Φ OTDR technique |
| CN106248119A (en) * | 2016-07-14 | 2016-12-21 | 南京大学 | A kind of distributed ultrahigh speed disturbance quantitative detecting method and device |
| CN206074149U (en) * | 2016-08-18 | 2017-04-05 | 盐城工学院 | A kind of temperature-detecting device being wirelessly transferred based on ZigBee |
-
2018
- 2018-02-08 CN CN201810128481.2A patent/CN108414112A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2440952A (en) * | 2006-08-16 | 2008-02-20 | Schlumberger Holdings | Measuring Brillouin backscatter from an optical fibre using digitisation |
| CN101825499A (en) * | 2010-05-18 | 2010-09-08 | 华北电力大学（保定） | Method for measuring sea water temperature profile based on optical fiber Brillouin scattering principle |
| JP2014167399A (en) * | 2013-02-28 | 2014-09-11 | Yokogawa Electric Corp | Optical fiber temperature distribution measuring device |
| CN103513147A (en) * | 2013-09-09 | 2014-01-15 | 华北电力大学（保定） | Submarine cable real-time monitoring system and submarine cable real-time monitoring method |
| CN105806465A (en) * | 2016-03-11 | 2016-07-27 | 南京大学 | Novel [phi]-OTDR detection device based on fixed reflection points and detection method thereof |
| CN106225907A (en) * | 2016-06-28 | 2016-12-14 | 浙江大学 | A kind of fiber-optic vibration identification system and method based on Φ OTDR technique |
| CN106197741A (en) * | 2016-07-14 | 2016-12-07 | 盐城工学院 | Temperature-detecting device based on micro-nano long-period fiber grating sensor and method |
| CN106248119A (en) * | 2016-07-14 | 2016-12-21 | 南京大学 | A kind of distributed ultrahigh speed disturbance quantitative detecting method and device |
| CN206074149U (en) * | 2016-08-18 | 2017-04-05 | 盐城工学院 | A kind of temperature-detecting device being wirelessly transferred based on ZigBee |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113804452A (en) * | 2021-07-30 | 2021-12-17 | 湖北三江航天万峰科技发展有限公司 | Distributed automobile fault monitoring system and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105806465B (en) | A kind of novel Φ-OTDR detection device and its detection method based on fixation reflex point | |
| CN104614602A (en) | Online monitoring device for arrester | |
| CN203433080U (en) | Non-contact electrical-equipment discharge-monitoring device based on technology of ultraviolet pulse detection | |
| CN102608452A (en) | High speed train equipment state and electric energy quality monitoring system and method | |
| CN103727968A (en) | Distributed type optical fiber sensing device and method for simultaneously measuring temperature, strain and vibration | |
| CN103389447A (en) | Non-contact ultraviolet pulse discharge monitoring device | |
| CN202329866U (en) | Fluorescent optical fiber temperature sensing demodulation instrument | |
| CN106482822A (en) | A kind of phase sensitive optical time domain reflection system of the detection that is concerned with based on double homologous heterodyne | |
| CN108414112A (en) | A kind of Discrete Production Workshop device temperature monitoring device and method based on Internet of Things | |
| CN102914518A (en) | Laser online sensing device and method for simultaneously measuring turbidity and particle size | |
| CN204115854U (en) | Based on the multichannel vibration detecting system of coherent rayleigh scattering | |
| CN204331954U (en) | A kind of precise positioning type optical fiber induction pre-alarm system | |
| CN102620861B (en) | Scaling temperature measuring device in distributed optical fiber temperature sensor | |
| CN202057808U (en) | Novel passage indicator | |
| CN207881831U (en) | A kind of distributed optical fiber vibration sensing device based on pulsed light | |
| CN216285656U (en) | Multi-loop leakage detection device | |
| CN108132094B (en) | Distributed optical fiber vibration sensing device and method based on pulsed light | |
| CN212694546U (en) | Single-ultraviolet double-infrared flame detector | |
| CN205373756U (en) | Temperature and humidity sensor | |
| CN202948533U (en) | Fiber grating fire detection system | |
| CN110505011A (en) | Fiber failure detection device | |
| CN208187590U (en) | A kind of wireless temperature measurement control system for fishery cultivating | |
| CN203433627U (en) | Point ultraviolet flame detector | |
| CN207036296U (en) | A kind of optical cable temperature measurement early warning system based on DTS | |
| CN209435224U (en) | A kind of electric power optical cable multi-path OTDR real time on-line monitoring device |
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 | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20180817 |