This part of IEC 61746 provides procedures for calibrating multimode optical time domain reflectometers (OTDR). It covers OTDR measurement errors and uncertainties. The test of the laser(s) source modal condition is included as an optional measurement.<\/p>\n
This standard does not cover correction of the OTDR response.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 6<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | 1 Scope 2 Normative references 3 Terms, definitions and symbols <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | Figures Figure 1 \u2013 Definition of attenuation dead zone <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 4 Preparation for calibration 4.1 Organization 4.2 Traceability 4.3 Preparation 4.4 Test conditions 4.5 Documentation <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 5 Distance calibration \u2013 General 5.1 General 5.2 Location deviation model <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | Figure 2 \u2013 Representation of the location deviation \u0394L(L) <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5.3 Using the calibration results Table 1 \u2013 Additional distance uncertainty <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 5.4 Measuring fibre length 6 Distance calibration methods 6.1 General 6.2 External source method <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Figure 3 \u2013 Equipment for calibration of the distance scale \u2013 External source method <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | Figure 4 \u2013 Set-up for calibrating the system insertion delay <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 6.3 Concatenated fibre method (using multimode fibres) Figure 5 \u2013 Concatenated fibres used for calibration of the distance scale <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 6.4 Recirculating delay line method <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | Figure 6 \u2013 Distance calibration with a recirculating delay line <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | Figure 7 \u2013 OTDR trace produced by recirculating delay line <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 7 Vertical scale calibration \u2013 General 7.1 General <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 7.2 Loss difference calibration Figure 8 \u2013 Determining the reference level and the displayed power level <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | Figure 9 \u2013 Region A, the recommended region for loss measurement samples Table 2 \u2013 Attenuation coefficients defining region A <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 7.3 Characterization of the OTDR source near field Figure 10 \u2013 Possible placement of sample points within region A <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 8 Loss difference calibration method 8.1 General 8.2 Long fibre method <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | Figure 11 \u2013 Linearity measurement with a long fibre Figure 12 \u2013 Placing the beginning of section D1 outside the attenuation dead zone <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | Annex A (normative) Multimode recirculating delay line for distance calibration Figure A.1 \u2013 Recirculating delay line <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | Figure A.2 \u2013 Measurement set-up for loop transit time Tb <\/td>\n<\/tr>\n | ||||||
| 41<\/td>\n | Figure A.3 \u2013 Calibration set-up for lead-in transit time Ta <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | Annex B (normative) Mathematical basis <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Calibration of optical time-domain reflectometers (OTDR) – OTDR for multimode fibres<\/b><\/p>\n |