training organisations authorised by BICSI (Building Industry
    Consulting Services International with headquarters in Tampa,
    Florida), Btec or City & Guilds.

5. The test equipment shall comprise optical power source and meter equipment in accordance with IEC 61280-4-1 (for multimode optical fibres) and IEC 61280-4-2 (for single mode optical fibres). The type of optical source and launch condition shall correspond with one of the categories defined in IEC 61280-4-1 (for multimode optical fibres) and IEC 61280-4-2 (for single mode optical fibres). The cabling interface adaptors consist of a number of test cords mating in accordance with IEC 61280-4-1 (for multimode optical fibres) and IEC 61280-4-2 (for single mode optical fibres). It is recommended to use a mandrel wrap and, where appropriate, cladding mode stripping techniques in order to maximise measurement repeatability. These should be established within the test cord. The mandrel used should be in accordance with IEC 61300-3-34 (5x20 mm for 62.5/125 ��m optical fibre, 5x15 mm for 50/125 ��m optical fibre).

6. The test equipment shall be within the calibration period recommended by the manufacturer in
order to achieve the manufacturer-specified measurement accuracy. This period is normally 12 months.

7. The fibre optic launch cables and adapters must be of high quality and the cables shall not show excessive wear resulting from repetitive coiling and storing of the test equipment interface adapters. No index matching gel shall be used.

8. The Pass or Fail condition for the link-under-test is determined by the results of the required individual tests (detailed in Section I.B). Field Test Specifications for Fibre Optic Installations Page 2 of 4

9. A Pass or Fail result for each parameter is determined by comparing the measured values with the specified test limits for that parameter.

10. Optional Requirements:

11. A representative of the end-user shall be invited to witness field testing. The representative shall be notified of the start date of the testing phase five (5) business days before testing commences.

12. A representative of the end-user will select a random sample of 5% of the installed links. The representative (or his authorized delegate) shall test these randomly selected links and the results are to be stored in accordance with the prescriptions in Section 0. The results obtained shall be compared to the data provided by the installation contractor. If more than 2% of the sample results differ in terms of the pass/fail determination, the installation contractor under supervision of the end-user representative shall repeat 100% testing and the cost shall be borne by the installation contractor.

B. Performance Test Parameters

1. EN50173 prescribes the single performance parameter for field testing of fibre optic links as link attenuation (alternative and equivalent term: insertion loss), when installing components compliant with this standard.
2. The link attenuation shall be calculated in accordance to the specifications within EN50173.
These specifications are representative of the following formulas.
Link Attenuation = Cable_Attn + Connector_Attn + Splice_Attn
Cable_Attn (dB) = Attenuation_Coefficient (dB/km) * Length (km)
The values for the Attenuation_Coefficient are listed in the table below:

Type of Optical Fiber(dB/km)	Wavelength (nm)	Attenuation_Coefficient(dB/km)
Multimode 62.5/125 ��m	850	3.5
	1300	1.5
Multimode 50/125 ��m	850	3.5
	1300	1.5
Single-mode	1310	1.0
	1550	1.0

Connector_Attn (dB) = number_of_connector_pairs * connector_loss (dB)
Maximum allowable connector_loss = 0.75 dB
Splice_Attn (dB) = number of splices (S) * splice_loss (dB)
Maximum allowable splice_loss = 0.3 dB
Link attenuation does not include any active devices or passive devices other than cable, connectors, and splices, i.e. link attenuation does not include such devices as optical bypass switches, couplers, repeaters, or optical amplifiers.
3. The above link test limits attenuation are based on the use of the One Reference Jumper Method specified by Method 1 of IEC 61280-4-1 for multimode and Method 1 of EN 61280-4-2 for singlemode or the equivalent method. The user shall follow the procedures established by these standards or application notes to accurately conduct performance testing.
Field Test Specifications for Fibre Optic Installations Page 3 of 4
4. The horizontal link (multimode): acceptable link attenuation for a multimode horizontal optical
fibre cabling system is based on the maximum 90 m distance. The horizontal link should be tested at 850 nm and 1300 nm in one direction in accordance with Method 1 of IEC 61280-4-1, One Reference Jumper method.
5. The backbone link (multimode) shall be tested in one direction at both operating wavelengths to account for attenuation deltas associated with wavelength.
6. Multimode backbone links shall be tested at 850 nm and 1300 nm in accordance with Method 1 of IEC 61280-4-1.
Because backbone length and the potential number of splices vary depending upon site conditions, the link attenuation equation (Section B.2) shall be used to determine limit (acceptance) values.
7. Singlemode backbone links shall be tested at 1310 nm and 1550 nm in accordance with IEC 61280-4-2, One Reference Jumper or the equivalent method. All singlemode links shall be certified with test tools using laser light sources at 1310 nm and 1550 nm (See Note below).
NOTE: Links destined to be used with network applications that use laser light sources (underfilled launch conditions) shall be tested with test equipment based on laser light sources categorized by a Coupled Power Ratio (CPR) of Category 2, Underfilled, per IEC 60825-2. This rule should be followed for cabling systems to support Gigabit Ethernet. Gigabit Ethernet only specifies laser light sources. Field test equipment based on LED (light emitting diode) light sources is a Category 1 device per IEC 60825-2 and typically yields high attenuation results.
For Gigabit Ethernet compliant certification (IEEE std 802.3z application), use test equipment which uses a VCSEL (Vertical cavity surface emitting laser) at 850 nm (compliant with 1000BASE-SX) and an FP laser at 1310 nm (compliant with 1000BASELX).
8. Optional requirement:Each fibre optical link terminated with an optical adapter system which does not impose a transmission direction because the adapters are not or cannot be ganged should be tested and documented in both direction since the direction of the signal transmission cannot be predicted at the time of installation.

C. Test Result Documentation

1. The test result information for each link shall be recorded in the memory of the field test equipment upon completion of the test.
2. The test result records saved by the test equipment shall be transferred into a Windows?- based database utility that allows for the maintenance, inspection and archiving of these test records. A guarantee must be made that these results are transferred to the PC unaltered, i.e., "as saved in the test equipment" at the end of each test. The popular 'csv' format (comma separated value format) does not provide adequate protection and shall not be acceptable.
3. The database for the completed job - including twisted-pair copper cabling links if applicable - shall be stored and delivered on CD-ROM; this CD-ROM shall include the software tools required to view, inspect, and print any selection of test reports.
4. A paper copy of the test results shall be provided that lists all the links that have been tested with the following summary information
      a) The identification of the link in accordance with the naming
           convention defined in the overall system documentation
      b) The overall Pass/Fail evaluation of the link-under-test including
           the Attenuation worst case margin (margin is defined as the
           difference between the measured value and the test limit
           value).
      c) The date and time the test results were saved in the memory of
           the test equipment
5. General Information to be provided in the electronic data base containing the test result
information for each link:
      a) The identification of the customer site as specified by the end-
           user
      b) The overall Pass/Fail evaluation of the link-under-test
      c) The name of the standard selected to execute the stored test
           results
      d) The cable type and the value of the 'index of refraction' used for
           length calculations
      e) The date and time the test results were saved in the memory of
           the test equipment
      f) The brand name, model and serial number of the test
           equipment
      g) The revision of the test equipment software and the revision of
           the test standards database in the test equipment
6. The detailed test results data to be provided in the electronic database for each tested optical fiber must contain the following information
      a) The identification of the link/fiber in accordance with the naming
           convention defined in the overall system documentation.
      b) The attenuation measured at each wavelength, the test limit
           calculated for the corresponding wavelength and the margin
           (difference between the measured attenuation and the test
           limit value).
      c) The link length shall be reported for each optical fibre for which
           the test limit was calculated based on the formulas in section
           B.2.