Terahertz Technologies Inc. Optical Time Domain Reflectometer
An Optical Time Domain Reflectometer (OTDR) trace is a graphical signature of a fiber's attenuation along its length. You can gain insight into the performance of the link components (cable, connectors and splices) and the quality of the installation by examining non-uniformities in the trace.
An OTDR trace helps characterize individual events that can often be invisible when conducting only loss/length (tier 1) testing. An OTDR is an important instrument used by organizations to certify the performance of new fiber optics links and detect problems with existing fiber links.
Maintaining Fiber Infrastructure Performance
OTDRs are also used for maintaining fiber plant performance. An OTDR allows you to see more detail impacted by the cabling installation. It maps the cabling and can illustrate termination quality, location of faults. It provides advanced diagnostics to isolate a point of failure that may hinder network performance. An OTDR allows discovery of issues along the length of a channel that may affect long term reliability. OTDRs characterize features such as attenuation uniformity and attenuation rate, segment length, location and insertion loss of connectors and splices, and other events such as sharp bends that may have been incurred during cable installation.
Selection advice for Optical Time Domain Reflectometers (OTDRs)
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Loss-length certification
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Channel/event map view
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Power meter capabilities
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Easy-to-use interface
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Smart-remote options
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Documentation and Certification capability
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Consider a Fiber Optic Test Kit. Then best value is to purchase a Fiber Optic Test Kit. See TEquipment website category by the same
What is a copper and fiber cable certification tester?
Certification test tools answer the question, “Does this cable comply with cabling standards?
(e.g. TIA/EIA-568-C , ISO/IEC 11801, ANSI/TIA 1152 (copper only), ISO/IEC 61935-1).
Certification is the most rigorous of all cable testing. A certification tester makes many types of measurements across predefined frequency ranges and compares the detailed results to standards. The results from these measurements determine if a link is compliant with a category or class of cable. Certification tools are the only tools that provide “Pass” or “Fail” information on the cabling, in accordance with TIA or ISO standards.
Cabling manufacturers often require certification before issuing a warranty and enterprises often require certification testing before commissioning an installation.
Who uses a copper and fiber cable certification tester?
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Commercial datacom installers/contractors and enterprise facility managers to ensure that new cabling fully meets performance standards.
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Network owner who wants to check their own and third party installations.
Functions of copper and fiber cable testers
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Verification Testers. Used to determine if the cable is properly connected. Verification test tools perform basic continuity functions (for example., wiremap, toning for copper). These verification test tools sometimes include additional features such as a Time Domain Reflectometer (TDR) or Optical Time Domain Reflectometer (OTDR) to determine the length of the cabling link or the distance to a break or a short circuit in the link-under-test. They may also support continuity of twisted-pair links as well as copper coaxial cabling links and check coaxial connections. Verification tools may also detect and report that the cable under test is connected to an active device like a hub or switch.
Verification tools are ubiquitous, simple-to use, low-cost tools that are often the first line of defense in finding cabling problems. Verification tools are especially valuable as a quick and easy screening tool when performing large-scale installations. They can be used to verify that cables have been correctly wired and terminated, and to find breaks and shorts before the certification tests are performed. Eliminating connectivity problems before the certification tests can save valuable time and can significantly reduce the overall costs of testing.
Light can go thru a broken window and a fiber, unless a clean break, but a verification tester does not tell you the health and quality, so just a step above continuity.
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Qualification Testers. Qualification is a new category of testers designed to meet the emerging needs of network technicians who need to upgrade to higher network speeds as well as troubleshoot connectivity problems. Qualification testers help determine if the cabling will support technology requirements like fast Ethernet, VoIP, Gigabit Ethernet, etc. This type of tool is sometimes erroneously called a “Speed Certifier”. If you are a network technician, and have undocumented cabling and need to see if it will support your 1000BASE-T network, a qualification tool is the right choice.
If you have an existing network and are doing small adds, moves, and changes, or you are setting up a temporary network and just need to qualify it for a specific network technology, a qualification tool is a good option.
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Certification Testers. Test the cabling to ensure that it meets specific cabling performance standards. A good certification tester is easy to use, but has the ability to quickly do complex and accurate calculations. If you have a mixture of fiber and copper cabling, and often need to test both, certification tools do that best. Gives you a better understanding of how close the cable is to failure or problem that a qualification tester cannot. Qualification can just tell you the speed at time of measurement.
Certification of new cabling per IEEE, TIA/EIA, or ISO/IEC standards is necessary to ensure that the link will run the intended application. Complete fiber cabling certification includes two parts
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Tier 1 or Basic Test Regimen. Tier one cabling certification is performed with a power meter and light source or optical loss test set to measure the absolute loss of the link and compare it to the limits in the standard. The Tier 1 tests are attenuation (insertion loss), length and polarity. When conducting Tier 1 testing, each fiber link is measured for attenuation and results are documented. This test ensures that the fiber link exhibits less loss than the maximum allowable loss budget for the immediate application. Most common certification.
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Tier 2 or Extended Test Regimen. Extended or Tier 2 fiber certification and troubleshooting supplements Tier 1 testing and can be performed with an OTDR . Visual Fault Locator is part of the test to help determine where is the loss along with the OTDR.
Example OTDR Trace Graph from an Optical Wavelength Laboratories (OWL) OTDR
with explanation of events
What is multimode and single mode fiber optic cable?
Certainly, there is much more information and science involved but the very basic differences:
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Single mode is for outside use over long distances. Higher bandwidth. Uses lasers which are more expensive, so not used for indoor applications
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Multiple modes of light in a wider core fiber cable using LED light. Shorter distances and less bandwidth, though there is ongoing research to increase bandwidth and distance to rival single mode