Optical fiber monitor using optical time domain reflectometer and monitoring method
US5943123A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1998 |
| Grant date | Aug 24, 1999 |
| Priority date | — |
| Expiry date | Mar 19, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/3145
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
First to fourth initial data memories 31a to 31d prestore initial data R obtained when a reference optical fiber 22 having a predetermined length was previously measured, and initial data Pa to Pc obtained when a to-be-monitored optical fiber was previously measured. A first arithmetic unit 33 finds a difference .alpha. between measurement data R' obtained when the reference optical fiber 22 is newly measured and the initial data R as a first drift amount representing a variation in characteristics of the OTDR itself. A second arithmetic unit 34 finds a difference .beta. between measurement data P' obtained when the to-be-monitored optical fiber 1 is newly measured and the initial data of the to-be-monitored optical fiber as a second drift amount representing a variation in characteristics of the OTDR itself and characteristics of the to-be-monitored optical fiber 1. A third arithmetic unit 35 finds, from a difference between .beta. and .alpha., a real characteristic variation amount .gamma. of the to-be-monitored optical fiber 1 as a third drift amount representing a variation in characteristics of the to-be-monitored optical fiber 1. A waveform comparator 36 detects the presence/…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.