1、 IEC TR 61282-14 Edition 2.0 2019-07 TECHNICAL REPORT Fibre optic communication system design guidelines Part 14:Determination of the uncertainties of attenuation measurements in fibre plants IEC TR 61282-14:2019-07(en)colourinside THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2019 IEC,Geneva,Sw
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9、nd Definitions clause of IEC publications issued since 2002.Some entries have been collected from earlier publications of IEC TC 37,77,86 and CISPR.IEC TR 61282-14 Edition 2.0 2019-07 TECHNICAL REPORT Fibre optic communication system design guidelines Part 14:Determination of the uncertainties of at
10、tenuation measurements in fibre plants INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 33.180.01 ISBN 978-2-8322-7069-1 Registered trademark of the International Electrotechnical Commission Warning!Make sure that you obtained this publication from an authorized distributor.colourinside 2 IEC TR 61282-
11、14:2019 IEC 2019 CONTENTS FOREWORD.5 INTRODUCTION.7 1 Scope.8 2 Normative references.8 3 Terms,definitions and abbreviated terms.8 3.1 Terms and definitions.8 3.2 Abbreviated terms.10 4 Overview of uncertainty.10 4.1 What is uncertainty?.10 4.2 Origin of uncertainties.11 4.3 What may not be consider
12、ed as uncertainty?.11 5 Fibre cabling attenuation measurement.11 5.1 Test methods.11 5.2 Sources of uncertainty to be considered.11 5.2.1 Analysis.11 5.2.2 Uncertainties due to the environment.14 5.2.3 Uncertainties due to operator skills.14 5.2.4 Uncertainties due to test methods.14 5.2.5 Uncertain
13、ties due to measuring instruments.14 5.2.6 Uncertainties due to the setup.16 5.2.7 Uncertainties due to cabling.16 6 Uncertainties estimation.17 6.1 Measurement model.17 6.2 Accumulation of uncertainties.19 7 General representation of the equation using sensitivity coefficients.19 8 Calculation.23 8
14、.1 Combined standard uncertainty.23 8.2 Expanded uncertainty.23 8.3 Determination of the coverage factor k.23 8.3.1 General approach.23 8.3.2 Discussion.23 8.3.3 Typical values of degree of freedom.24 Annex A(informative)Mathematical basis.25 A.1 General.25 A.2 Type A evaluation of uncertainty.25 A.
15、3 Type B evaluation of uncertainty.25 A.4 Determining the combined standard uncertainty.26 A.5 Reporting.27 Annex B(informative)Test methods.28 B.1 Test methods as per IEC 61280-4-1 and 61280-4-2.28 B.1.1 General.28 B.1.2 Measurement configuration.28 B.1.3 One-cord reference configuration.28 B.1.4 T
16、wo-cord reference configuration.29 B.1.5 Three-cord reference configuration.29 IEC TR 61282-14:2019 IEC 2019 3 B.2 Test methods defined in ISO/IEC 14763-3:2014.29 B.2.1 General.29 B.2.2 Channels.30 B.2.3 Links.31 Annex C(informative)Uncertainties evaluation.32 C.1 Type A uncertainties.32 C.1.1 General.32 C.1.2 Evaluation of optical source instability and associated uncertainties.32 C.2 Type B uncertainties.32 C.2.1 General.32 C.2.2 Evaluation of the power meter noise.32 C.2.3 Elements to be cons
