JJG 959-2001 Verification Procedure for Optical Time Domain Reflectometer JJG959-2001 Standard download decompression password: www.bzxz.net
This procedure applies to the initial verification and subsequent verification of optical time domain reflectometer.

National Metrology Verification Regulation of the People's Republic of China JJG959-2001
Optical Time Domain Reflectometer
Optical Time Domain Reflectoteler2001－02-01Published
2001-05·01Implemented
State Administration of Quality and Technical SupervisionPublished
JJG959—2001
Optical Time Domain Reflectometer (OTDR)
Verification Regulation ot OpticalTimeDomain Rcfleetomeler
JJG959—2001
This regulation was approved by the State Administration of Quality and Technical Supervision on February 1, 2001, and will be implemented on May 1, 2001.
Responsible unit: National Technical Committee for Geometry and Length Metrology Drafting unit:
China National Institute of Metrology
This regulation is entrusted to the National Technical Committee for Geometry and Length Metrology to be responsible for the interpretation of this regulation. Main drafters of this regulation:
Fang Yuwen
Participating drafters:
Li Tianren
Wang Minming
Li Wansong
Zhang Chengping
JJG955-2001
[National Institute of Metrology]
(China National Institute of Metrology)||t t||(China Institute of Metrology)
(China Institute of Metrology)
(China Institute of Metrology and Basic Sciences)
Metrological performance requirements
Central wavelength of optical wave
Expanded uncertainty of distance measurement
Expanded uncertainty of batch measurement
Setting deviation
Moving range,
Length of “reduce white zone”
Length of “event zone”
General technical requirements
Technical data
Function keys·
Control of measuring instruments
First verification and subsequent verification
Verification conditions
Verification items and verification methods
Handling of verification results
Verification cycle
Appendix A
JJG $59--2001
Optical Time Domain Reflectometer Basic Format Record
(3)
(3)
1 Scope
JJG959-2001
Optical Time Domain Reflectometer Calibration Procedure
This procedure applies to the initial and subsequent calibration of the Optical Time Domain Reflectometer (OTDR). 2 Terminology
2.1 Center Wavelength (Center Wavelength)
The weighted average vacuum wavelength of the light source represented by m. For a continuous spectrum, the center wavelength is defined as
The separated light
Formula: P:-
The spectral power density of the light source;
2:——Discrete wavelength,
-: wavelength, the power density of the optical mode.
2.2 Drado
The distance between the characteristic points of the optical fiber determined by a measuring instrument with higher accuracy than OTDR (m): 2.3 Distance scale factor (S1)
The average displayed distance of OTDR is divided by the corresponding reference distance Sr
Where: Drado
(Datr)
The average displayed distance of OIDR measurement reference distance 2.4 Reference tolerance (Lr)||t t||The distance between the front panel of the TDR and a characteristic point of the optical fiber determined by a measuring standard or measuring instrument with higher accuracy than TDR (m)bzxZ.net
2.5 bit deviation1
\ID measurement reference position The displayed value of the characteristic point minus the reference position (m) (approximately equal to the displayed position of the TDR output connector at the OTLR distance scale. For an ideal OTLR, this value should be 1
JJC959-2001
AL.= Ledr -L
Where: The display of the measured reference position. .Taiko loss (AF
The loss of an optical element accurately calibrated by the method of direct identification of a variable frequency scale () 2.7 Loss scale factor (S)
The ratio of simulated loss to reference loss ()
Where: Ad—Measurement of reference loss of the OTDR. 2.8 Standard deviation (4S,)
The difference between the displayed value of the measured reference root loss A and the reference loss A divided by the reference loss (eBdB):
Andr - A
29 The dynamic range of the backscattering process
makes the backscattered signal equal to the attenuation of the noise level. It is called the [E] type 1 optical test, which is represented by the power between the intersection of the extrapolated axis of the backscattering curve and the actual level (signal ratio S
2.10 "return zone length
the period after the last reflected magnetic event. The beginning of this zone is the rising point before the event, and the end is 0 The trajectory of the deviation from the original school must pass through a given vertical coordinate AF (positive and negative), and its projection length on the horizontal coordinate (left) is the "attenuation zone length". 2.11 "Event length
For a specific reflection return loss, the distance between the two points of the low reflection peak point 1.5B on the reflection trajectory is the "attenuation zone", and its projection as the horizontal coordinate distance is the "event zone" length. 3. Speed ​​
Optical time reflection meter (Optical Time Domain Reflectomer) emits a light pulse to the end of the optical fiber, and then receives the backscattered light and the reflected light from the end of the optical fiber to obtain the fiber length information. The optical time domain reflectometer is used to measure the transmission and distribution of single-mode or multi-mode optical fibers and the length of the optical fiber and the location of the fault point. The instrument (hereinafter referred to as the instrument) is shown in Figure 1. The light source () of the optical time domain reflectometer (OTD reflectometer) emits a light pulse, which is injected into the measured optical fiber through the instrument. The backscattered and non-reflected signals received by the optical receiver are a light intensity signal produced in time sequence. The signal at each moment is a Fresnel frequency signal corresponding to the backscattered position of the light. The receiver converts the optical signal into an electrical signal, sends it to the signal processing system and the computer for processing and operation, and displays the distribution of the light intensity returned from the entire section. LD
Green pulse generator
4 Metrological performance requirements
4.1 Output light center wavelength
JJG959—2001
Tree cooperation
Optical output receiver
Signal processing system
1310nm window: [1310+20)nm
1550nm window: (1550-20)nm;
Or according to the technical specification of the device to be inspected, 4.2 Distance measurement uncertainty
4.3 Distance measurement expansion Uncertainty of development
4.4 Adjustment
4.5 Dynamic range
Length of "blind zone"
Length of "event blind zone"
4.2～4.7 According to the technical specifications of the instrument to be inspected. 5 General technical requirements
5.1 Punctuation
Measured optical fiber
The instrument store shall have a sign indicating the name, model, manufacturing name, production number, matching mark and serial number of the plug-in.
5.2 Technical information
Attached with the above information provided by the manufacturer Technical specifications describing metrological performance, product certificates and related attachments. 3
The inspected instrument should be accompanied by the last calibration certificate: 5.3 Appearance
JJG95920Q1
The inspected instrument should not have mechanical defects that affect the working performance: 5.4 Function chain
The various switches and buttons of the inspected instrument are clearly marked. The switches, buttons, etc. have good contact and work normally. The screen display is clear.
6 Control of measuring instruments
6.1 Initial calibration and subsequent calibration
The first calibration and subsequent calibration The design and technical changes of the calibration shall comply with the requirements of 4.1~4.7 and 5.-5.4 of this regulation.
6.2. Calibration conditions
6.2.1 Measuring standard
6.2.1.1 Length standard optical fiber
Fiber optical length calibration extended uncertainty: U-(0.2+1.5×10-3L)11.61.2.1.2 Loss standard push light or simulated joint light red loss calibration extended uncertainty range:
1310nm=0.03dB/0B:
1550 nm U = 4.03 dB/dB.
6.2.2 Other calibration equipment
6.2.2.1 Wavelength meter or optical harmonic analyzer
Center wavelength measurement expanded uncertainty:
1310mml-2.0nm;
1550nm-2.0
Wavelength resolution: better than 0.5nm
6.2.2.2 Time synthesizer
Synthesis time range: 0-·3m%, can be adjusted at will, resolution better than 100P5: Output pulse width: (1-·10) retreat, adjustable: withdrawal pulse amplitude: 501 resistance, (0 .5-5) V adjustable, positive and negative polarity selectable; Jitter: not more than 200prm%
Time base expansion uncertainty: better than 1×10: (for the selected collection time) Total expansion uncertainty: better than 1.5s Add time base expansion uncertainty: 6.2.2.3 Photon subtraction
Variable attenuator: one, with a range of and;
Calibrated high repeatability attenuator: one, (1-·4)dB, resolution better than 0.001dB, reproducibility better than 4
JJG $9—2001
Wavelength range: [310 m and 1550 nm;
Input loss: <2.5dF;
Back reflection loss: >45;
Attenuation spread uncertainty: optimum 1 certification: the above frequencies are included in the frequency band = 21
Maximum allowable input optical power: >200m,
6.2.2.4 Photosynthesizer
Two Y-type 50:50 couplers, one Y-type 10:0 combiner Wavelength range: 1310am and 1550nm Window: total insertion loss <0.3dB, single-channel insertion loss spectrum is known, back reflection loss >51R6.2.2.5 Optoelectronic converter (0/E)
Wavelength range: 1310nm and 1550nm
Bandwidth DC~200MHx or higher, conversion gain and output impedance should meet the requirements of the external contact signal of the optical synthesizer.
G.2.2.6 Optical converter (E/0)
FP type laser, wavelength range (13F0±10) nm; (1550±10) nm bandwidth LXC -100 MHz or higher.
Standard deviation of output optical pulse amplitude variation after external modulation
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