This part of IEC 60793 establishes uniform requirements for measuring the attenuation of optical fibre, thereby assisting in the inspection of fibres and cables for commercial purposes.<\/p>\n
Four methods are described for measuring attenuation, one being that for modelling spectral attenuation:<\/p>\n
method A: cut-back;<\/p>\n<\/li>\n
method B: insertion loss;<\/p>\n<\/li>\n
method C: backscattering;<\/p>\n<\/li>\n
method D: modelling spectral attenuation.<\/p>\n<\/li>\n<\/ul>\n
Methods A to C apply to the measurement of attenuation for all categories of the following fibres:<\/p>\n
class A multimode fibres;<\/p>\n<\/li>\n
class B single-mode fibres.<\/p>\n<\/li>\n<\/ul>\n
Method C, backscattering, also covers the location, losses and characterization of point discontinuities.<\/p>\n
Method D is applicable only to class B fibres.<\/p>\n
Information common to all four methods appears in Clauses 1 to 11, and information pertaining to each individual method appears in Annexes A, B, C, and D, respectively.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | Annex ZA(normative)Normative references to international publicationswith their corresponding European publications <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 4 Calibration requirements 5 Reference test method 6 Apparatus 7 Sampling and specimens 7.1 Specimen length 7.2 Specimen end face 8 Procedure 9 Calculations 9.1 Methods A and B 9.2 Method C 9.3 Method D 10 Results 10.1 Information available with each measurement <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 10.2 Information available upon request 10.3 Method-specific additional information 11 Specification information <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | Annexes Annex A (normative) Requirements specific to method A \u2013 Cut-back A.1 General A.2 Apparatus A.2.1 General apparatus for all fibres Figure A.1 \u2013 Arrangement of equipment for loss measurement ata specified wavelength <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | Figures Figure A.2 \u2013 Arrangement of equipment used to obtain loss spectrum Figure A.3 \u2013 General launch arrangement <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | A.2.2 Launch apparatus for all single-mode fibres <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | A.2.3 Launch apparatus for A1 multimode fibres <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Figure A.4 \u2013 Limited phase space launch optics Tables Table A.1 \u2013 Size examples <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | A.2.4 Launch apparatus for A2 to A4 multimode fibres Figure A.5 \u2013 Two examples of optical fibre scramblers Figure A.6 \u2013 Lens system Table A.2 \u2013 Launch conditions for A2 to A4 fibres <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | A.2.5 Calibration requirements Figure A.7 \u2013 Launch fibre Figure A.8 \u2013 Mode scrambler (for A.4 fibre) <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | A.3 Procedure A.4 Calculations Figure A.9 \u2013 A wide-spectrum source (line “b”) could lead to attenuation measurement errors due to sharp variations on spectral attenuation of polymer-core fibres (line “a”) <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | Annex B (normative) Requirements specific to method B \u2013 Insertion loss B.1 General B.2 Apparatus B.2.1 General set-ups B.2.2 Apparatus common to method A (cut-back) B.2.3 Additional apparatus specific to method B (insertion-loss) B.2.4 Calibration requirements B.3 Procedure <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | B.4 Calculations Figure B.1 \u2013 Calibration of insertion loss measurement set Figure B.2 \u2013 Measurement of insertion loss <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | Annex C (normative) Requirements specific to method C \u2013 Backscattering C.1 General C.2 Apparatus C.2.1 General Figure C.1 \u2013 Block diagram of an OTDR <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | C.2.2 Optical transmitter C.2.3 Launch conditions C.2.4 Optical splitter C.2.5 Optical receiver C.2.6 Pulse duration and repetition rate C.2.7 Signal processor <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | C.2.8 Display C.2.9 Data interface (optional) C.2.10 Reflection controller (optional) C.2.11 Splices and connectors C.3 Sampling and specimens C.4 Procedure C.4.1 General <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Figure C.2 \u2013 Schematic OTDR trace for a “uniform” specimen preceded by a dead-zone fibre Figure C.3 \u2013 Schematic OTDR trace for a “uniform” specimen not preceded by a dead-zone fibre <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | C.4.2 Further steps for measuring attenuation C.4.3 Further steps for measuring point discontinuities <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | Figure C.4 \u2013 Schematic OTDR trace showing apparent loss due to point discontinuities, one reflective and one non-reflective Figure C.5 \u2013 Schematic of an expanded OTDR trace showing two point discontinuities, one with apparent gain, and another with no apparent loss or gain <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | C.4.4 Calibration C.5 Calculations C.6 Results <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | Annex D (normative) Requirements specific to method D \u2013 Spectral attenuation modelling D.1 General D.2 Apparatus D.3 Sampling and specimens D.4 Procedure <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | D.5 Calculations D.6 Results <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | Annex E (informative) Examples of short cable test results on A1 multimode fibres Figure E.1 \u2013 Example of attenuation coefficient tests on A1a.1 fibre Figure E.2 \u2013 Example of attenuation coefficient tests on A1a.3 fibre <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Figure E.3 \u2013 Example of attenuation coefficient tests on A1b fibre <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Optical fibres – Attenuation measurement methods<\/b><\/p>\n |