What is an OTDR?
An OTDR combines a laser source and a detector to provide an inside view of the fiber link. The laser source sends a signal into the fiber where the detector receives the light reflected from the different elements of the link. This produces a trace on a graph made in accordance with the signal received, and a post-analysis event table that contains complete information on each network component is then generated. The signal that is sent is a short pulse that carries a certain amount of energy. A clock then precisely calculates the time of flight of the pulse, and time is converted into distance—knowing the properties of this fiber. As the pulse travels along the fiber, a small portion of the pulse’s energy returns back to the detector due to the reflection of the connections and the fiber itself. When the pulse has entirely returned to the detector, another pulse is sent—until the acquisition time is complete. Therefore, many acquisitions will be performed and averaged in a second to
An Optical Time Domain Reflectometer (OTDR) is used in fiber optics to measure the time and intensity of the light reflected on an optical fiber. More to the point, it is used as a troubleshooting device to find faults, splices, and bends in fiber optic cables, with an eye toward identifying light loss. Light loss is especially important in fiber optic cables because it can interfere with the transmission of data. An OTDR can detect such light loss and pinpoint trouble areas, making repairs easy. The more quickly trouble areas are identified and addressed, the less your fiber optic network will suffer from data transfer problems. The physical description of an OTDR most closely resembles a sort of handheld price scanner with cables attached. The user connects the cables to an optical fiber, in the same way that two drivers will connect vehicle batteries with jumper cables, and then reset the OTDR settings for whatever parameters are being used in the specific test. A typical OTDR test
Many times our customers ask: “Do I need to do OTDR testing, or power meter testing?” The answer to this question lies in what are you trying to determine: 1)If there is a break on the fiber, you must use an OTDR. 2)If you want to use a particular piece of equipment on the fiber, and you need to determine the loss of the fiber, you use a power meter/light source. To help with this we have outlined the definition of an OTDR: optical time domain reflectometer (OTDR): An opto-electronic instrument used to characterize an optical fiber. Note 1: An OTDR injects a series of optical pulses into the fiber under test. It also extracts, from the same end of the fiber, light that is scattered back and reflected back. The intensity of the return pulses is measured and integrated as a function of time, and is plotted as a function of fiber length. Note 2: An OTDR may be used for estimating the fiber’s length and overall attenuation, including splice and mated-connector losses. It may also be used t
