Optical Fibre Testing

OPTICAL FIBRE TESTING FOR COMPLIANCE TO ISO/IEC 11801

1 All Optical Fibres, including Pre-Terminated Optical Fibres shall be CLEANED after installation and tested as a LINK for:

1) Visual inspection of all ends Recommended 2) Continuity and Maintenance of Polarity Required 3) Length Required 4) Propagation Delay Required 5) Optical Attenuation of Link: 2 x wavelengths Required (See Item 16) [OF LINKS and CHANNELS both include the 2 x end connectors when testing.]

2 Visual inspection is not mandatory but if done, use a minimum x100

magnification for MMF, x200 for SMF, both conducted to protect the viewers eyes. The core is a PASS if it is round, clear & featureless. The inner 1/2 of cladding is a PASS if it is free of chips & cracks but it may have some polishing marks

YES Use the 1-Test Cord Method of Reference Setting (Method -B) (Eg. SC on tester and SC on both ends of Link) NO Use the 3-Test Cord Method of Reference Setting (Method C) (Eg. SC on Tester and LC on Link) The test results shall show the LSPM reference setting method used. Where possible , record the manufacturer and type of all test cords and mandrel diameter used.

9 Use of Mandrels or Coils (for both 1 & 3-Test Cord Methods) For MMF, the LSPM Tester must have the correct Coupling Power Ratio for the cable under test. Alternatively, this can be achieved by using a Mandrel Wrap on the Launch Cord for mode stripping during Reference Setting and Testing. For a 3 mm Launch Cord, 5 turns on 17 mm for 62.5 m (OM1)

5 turns on 22 mm for 50 m (OM2 and OM3) For SMF, the LSPM launch cord shall have at least 2 x turns of 405 mm diameter, air-coiled or on a mandrel, for stripping light out of the cladding and more consistent readings.

10 Test Cord Qualification (for both 1 & 3-Test Cord Methods) All Test Cords & Field Calibration cords shall be Qualified. (See Item 17) Launch and Tail Cords for MMF & SMF LSPM testing shall be 1m to 5m each

and shall have a Reference Connector at one end. Field Calibration Cord shall not exceed 2m in length and shall have Reference

Connectors at both ends [used only with 3-Test Cord Method].

Reference Connectors are high precision connector terminations that ensure the core is central to the connector. They shall be the same type of connectors as the cabling under test. Mated Reference Connectors shall have an attenuation of 0.10

dB for MMF, and 0.20 dB for SMF.

11 Field Calibration Cord Removal (for 3-Test Cord Method)

For both MMF and SMF cabling, after the 3-Test Cord Reference Setting has been done, the central Field Calibration Cord shall be removed and the cabling under test connected.

12 Compliance criteria for an ADC KRONE Warranty is; 1. Continuity & Polarity shall be correct, and 2. Length shall be recorded, and 3. Propogation Delay shall be recorded, and 4. Optical Attenuation (Power Loss) test result shall be less than the Power Loss

Budget at both the nominated wavelengths, in both directions for 1/10GBE installations. (Item 16)

13 Power Loss Budget (PLB) in dB is the sum of the maximum component

insertion loss allowed under ISO/IEC 11801 Table 4, AS/NZS 3080, Cl 9.4 Table 26, and Cl 10.3 Table 46. PLB = Loss from (Connectors + Splices + Cable). Values are set out in Item 14.

14 Component Power Loss

Component and Wavelength

ISO/IEC 11801 Insertion Loss Maximum

Mated RC to NC Connector

at 850 & 1300 nm at 1310 & 1550 nm

See Note 1 MMF 0.30 dB SMF 0.50 dB

Splice at 850 & 1300 nm

and at 1310 & 1550 nm

0.30 dB

MMF at 850 nm at 1300 nm

3.50 dB/km 1.50 dB/km

SMF at 1310 & 1550 nm

1.00 dB/km

Note 1. Insertion Loss {Ref ISO/IEC 14763-3 Tables 3 & 4} Mated RC to RC is 0.10 dB MMF and 0.20 dB SMF Mated RC to NC is 0.30 dB MMF and 0.50 dB SMF Mated NC to NC is 0.75 dB MMF and SMF Where RC = Reference connector Termination and NC = Non-reference connector Termination

1 x Mated Connection i.e. one Ref/Non-Ref Connection

1/2 1/2

RC Reference Connector

NC Connector on cabling

Connector device (general)

15 Example A fibre link consists of 198m

OM3, 50/125 m cable. In addition, there is a 1m pigtail splice inside the FOBOT at each end. What is the Power Loss Budget? PLB850 = 2 x RC/NC connectors + 2 x splices + 0.2 km x MMF PLB850 = 2 x 0.30 + 2 x 0.30 + 0.2 x 3.50 PLB850 = 1.90 dB maximum @ 850 nm PLB1300 = 2 x RC/NC connectors + 2 x splices + 0.2km x MMF PLB1300 = 2 x 0.30 + 2 x 0.30 + 0.2 x 1.50 PLB1300 = 1.50 dB maximum @ 1300 nm Therefore, the tester readings must be less than the maximum Power Loss Budget of;

16 Test Wavelength and Direction Horizontal & Backbone Cabling, Within The Same Building Where the MMF and SMF Link is to be used for 1/10GBE or is a channel or has unknown connectors, the test shall be done at: Both wavelengths, in 2 x direction using LSPM with Launch & Tail Cords. The single reported Test Result at each wavelength shall be the single highest reading from either direction, recorded to 2 decimal places. { Ref ISO/IEC 14763-3 Cl 9.1.1.3}

(Not the lowest reading, and not an average reading of both directions for LSPM testing) Some installers choose to use only OTDR testing and not do LSPM testing. If this is done, ADC KRONE will only accept the results if the average highest OTDR reading from both directions is calculated and written into an electronic record of results along with the PLB. For MMF and SMF Links that have known connectors and are not for 1/10GBE, test at; Both wavelengths, in just 1 x direction using LSPM with Launch & Tail Cords. Inter-building Campus Cabling Use LSPM 2 x wavelengths, both in 2 x directions, AND ALSO Use OTDR For Links less than 300m, Its not an ADC KRONE requirement.

For Links over 300m long, It is an ADC KRONE requirement.

2 x wavelengths, both in 2 x directions, using OTDR with launch and tail cords.

For OTDR tests, the single reported Test Result at each wavelength shall be the average of the highest readings from both directions. {Ref ISO/IEC 14763-3 Cl 9.1.2.4} [Because the scattering coefficients are usually different between launch cord, cable under test, and tail cord, the test results will be different when tested in different directions. So the readings are to be averaged for OTDR testing.]

PLB850 = 1.90 dB PLB1300 = 1.50 dB

There must always be a power loss. If there is a power gain, the testers need a new Reference Setting. See Item 19.

Item 15 Example

198m

FD

ER

1

1

1m Splice

1m Splice

At Launch Cord & Tail Cord

17 OTDR Testing, General Requirements 1. Use a Launch Cord and a Tail Cord for OTDR testing.

This stabilises the trace and allows the first and last connectors to be easily seen.

2. These Launch and tail Cords are different from those used in LSPM Testing. 2. oth Launch Cord and Tail Cord must be longer than the Dead Zone of the

OTDR. 3. The Launch Cord should be at least 20% greater in length than the Tail Cord. 4. ADC KRONE preferences are Launch Cord 100m min, Tail Cord 50m min. 5. On short installed lengths (

19 OTDR Testing, Unacceptable Results Due To Ghosting Ghosting is the presence of multiple peaks in an OTDR trace due to repeated reflections. Ghosts do not add or subtract optical power from trace characterisation, but they do make it very difficult to effectively interpret the OTDR trace. The OTDR and the test set up should be managed in such a way that ghosts are not present in the main part of the OTDR trace. Using long Launch and Tail Cords of different lengths helps manage ghosts. See Item 25.

OTDR Result showing Ghosting that could make it difficult to obtain accurate test results.

20 Quality Planning in ISO/IEC 14763-3 Annex E (Informative) of ISO/IEC 14763-3 sets out the Stages available for OF testing. For an ADC KRONE Warranty, the following are required; Stage 1 On-site Component Testing Not Required Stage 2 Basic Test Group Required [To determine conformance to ISO/IEC 11801] (See Items 1 and 16 of this document) Stage 2 Extended Test Group Use OTDR to find failure location [Used to investigate failures]

Appendix A (Informative)

AJ-PCHighlight

AJ-PCHighlight

AJ-PCHighlight

Set Up for Fluke DTX and DSP Series with Fibre Test Head as an LSPM Tester The Fluke DTX and DSP 4xxx with FTA 410 or 420 Fibre Test Heads is a Light Source and Power Meter (LSPM) tester and is set up as follows for an ADC KRONE Warranted site. For SC connectors, set the Zero Reference Setting using the appropriate method B as set out on pages B-1 to B-3.

Tester Parameter Value

Test Standard DTX Testers

DSP Testers

ISO / IEC 14763-3 ISO 11801 Link FTA410/420

Cable Type 62.5 for OM1

50 for OM2 and OM3

Remote End Configuration

Smart Remote (for 2 fibre testing)

Length Units

Metres

Bi-Directional Autotest

Enabled

Adaptor Type SC or LC or ST . (to suit connectors)

Number of Adaptors

2 for 1- Test Cord, Method B, or 0 for 3- Test Cord , Method C( see Note 1) Any more Adaptor than these may be assessed as a FAIL.

Number of Splices 0 (or 2, if 2 spliced pigtail were used)

Index of Refraction OM1

OM2 OM3

OS1

850 nm 1330 nm

1.496 1.487

1.483 1.479

1.481 1.476

1310 nm 1550 nm

1.4672 1.4683

Note 1

When setting up the LSPM tester, the Number of Adaptors is the number of (extra) adaptors ADDED AFTER REFERENCE SETTING regardless of which reference method is used. The 1-test cord Method B uses 0 adaptors during reference settings and 2 adaptors when testing; therefore set the (extra) number of adaptors 2. The 3-test cord Method C uses 2 adaptors during reference settings and 2 adaptors when testing; therefore set the (extra) number of adaptors 0. The latest software for Test Standard ISO/IEC 14763-3 already has correct adaptor loss values included for the 1-Test cord and 3-Test Cord methods. So set DTX tester to ISO/IEC 14763-3. When Bi-Directional testing, the test stops way through and prompts to swap the fiber connections.