Why Do You Need OTDR Launch Box and What Is It Used for?
HOLIGHT Fiber Optic Co., Ltd
Leading Provider of Passive Fiber Optic Product.
OTDR Launch Box is also an indispensable fiber tool in fiber optics. Why do we say that? The Optical Time Domain Reflectometer (OTDR) is a mandatory fiber optic testing tool that uses light backscattering technologies to analyze optical fiber performance. It can test the light loss and locate the fiber optic network's breaks, splices, and connectors. OTDR can test fiber loss and locate faults in fiber links. OTDR launch box, according to its function and working principle, has many other names, such as dead zone box, pulse suppressor, fiber ring, fiber optic launch cable, etc.
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What is the OTDR Launch Box?
OTDR launch boxes are available in various packages. Whether they are called fiber optic launch boxes, launch pulse suppressors, or OTDR launch cables, they all perform the same task. Technicians conduct quality tests to look for cable breaks and light loss in installed networks to eliminate cable breaks known as "dead zones." The "dead zone" is a blind spot that prevents you from seeing attenuation-causing events in the cable under test. It occurs when light is too intense when it initially leaves the OTDR. The OTDR launch box removes "dead zones" when testing fiber optic cables with OTDR test equipment. The Fiber Launch Box measures the relative loss of the near-end, and far-end launch ends connected to the patch panel. There is a long fiber optic spool with pigtails at both ends. One pigtail is used for the input, which is connected to the OTDR, and the other is used for the output, which is connected to the fiber under the test. The OTDR Launch Box is used to test the attenuation of the fiber optic cable when connected to the corresponding port. We offer a wide range of multi-mode cable box products for OTDR testing and handling high transmit power, which can be used with different connectors such as SC and LC.???
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What is the OTDR Dead Zone?
Many factors cause OTDR dead zones. The dead zone prevents the OTDR from identifying between bends, other connectors, breaks, or shattering. In technical terms, the OTDR dead zone is the distance at which the OTDR cannot detect any event or object on the fiber optic cable. Dead zones are a major drawback of OTDRs, especially in applications with many fiber optic components. Therefore, it is important to minimize the effects of the dead zone as much as possible. Therefore, the OTDR launch box is very important when performing OTDR testing, as it acts as an interface between the OTDR and the fiber optic system under test.
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Why Can Launch Fiber Overcome OTDR Dead Zone?
The OTDR inserts light pulses into the fiber cable and measures the back reflections caused by fiber faults to locate the light spot. If you need to test a very long fiber cable, insert a lot of optical power into the fiber to ensure that the light can be seen at the other end. If the powerful optical pulse is inserted into the optical fiber, the pulse width of the emitted optical signal will increase, which will cause a dead zone in a section of yarn and affect the test results of OTDR. This dead zone can be hundreds or thousands of meters long.
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Minimize the effects of OTDR dead zones during fiber testing. Add a long enough length between the OTDR and the fiber under test. This way, the OTDR dead zone will appear in this additional fiber. The launch fiber is long enough to cover the dead zone of the OTDR to improve test accuracy. Launch fibers are typically terminated with a connector at each end to connect the OTDR to the fiber cable under test.
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Basic of OTDR Launch Box
The dead zone of OTDR is caused by the high reflection levels, which may extend beyond 100 meters of OTDR due to the influence of pulse width. It is recommended to use the full length of fiber before the fiber is under test. Therefore, the receiver of the OTDR can have enough time to stabilize. The OTDR launch box is a long optical fiber inserted between the fiber under test and the OTDR, which can ensure that the OTDR dead zone occurs in the OTDR launch box (as shown in the figure below). In this way, the optical fiber cable under test will not be greatly affected by the dead zone of the OTDR.
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Design Styles of OTDR Launch Box
Our small, compact round box features shatterproof and dustproof housing that protects the cable from weather and wind. The 3-meter-long robust tail allows users much flexibility when testing in the tight spaces of fiber optic networks.
Our range of cable harnesses is ideal for testing, certifying, and maintaining all-fiber networks that use OTDR equipment to eliminate "dead zones."
Available with most contact configurations SC / APC - LC / APC and SC / UPC - LC / UPC in various standard lengths, 150, 500, 1000m, and 2000m consisting of OS2 G652D / G657A1, OM1 / OM2, OM3, and OM4 fiber, etc. We can provide other configurations according to your request.
When using an OTDR to measure fiber optic cables, our launch boxes help minimize the impact of the OTDR launch pulse, thereby improving measurement accuracy. Our high-quality launch boxes are available in three housing styles:
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1.?Yellow Type - OTDR Launch Box
They are designed to aid in testing fiber optic cable using an OTDR. The OTDR Launch Fiber box is used with Optical Time Domain Reflectometers (OTDRs) to help minimize the effects of the OTDR's launch pulse on measurement uncertainty. Available in many different configurations and fiber lengths.
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2. Aluminum Alloy Type - OTDR Launch Box
OTDR Launch Fiber box is used with Optical Time Domain Reflect meters (OTDRs) to help minimize the effects of the OTDR's launch pulse on measurement uncertainty. Now it is available in a compact, cute rugged box with customized adaptors or patch cords outside. We guarantee that there is no splicing in this whole kit!
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3. Ring Type - OTDR Launch Box
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Which OTDR Launch Box Fit Your Applications?
The OTDR launch box has many packaging forms; the most commonly used is the box type. It has a long fiber optic spool with connectors on both ends. One end of the input is connected to the OTDR, and the other end of the output is connected to the fiber under test. After clicking the corresponding ports on the input and output ports, you can use the OTDR launch box to test the attenuation of the optical fiber cable.
Using the OTDR launch box seems very simple. However, they should be careful with their handling. If accurate fiber cable test results are to be obtained, the fiber length in the OTDR launch box must be long enough to cover the entire blind zone. OTDR launch boxes, like fiber optic cables, come in different types. And one cannot be used in all fiber cable tests. We should mainly focus on 2 points:
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OTDR Test with Launch Fiber
There are two main designs of OTDR launch fiber, one is the fiber ring design, and the other is the box design, which is called launch fiber ring and OTDR launch box or OTDR dead zone box, respectively. Their use is essentially the same. Here are two cases of how to use OTDR launch fiber.
In some cables, the launch cable covers the dead zone at the beginning of the fiber link. In these cases, an OTDR launch fiber or OTDR launch box is deployed between the OTDR and the near-end connection, as shown in the diagram above. This allows accurate measurement of fiber loss at the near-end connection.
In some cases, the fiber loss at the far-end connection should also be tested. The launch fiber can then be installed and added as a receive cable at the far-end link, as shown in the image above.
Please note that the launch fiber you use for testing should be the same fiber type (OS2, OM1, OM2, OM3, OM4) as the fiber under test.
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Conclusion
After the OTDR launch box is inserted between the OTDR and the optical fiber under test, the influence of the OTDR dead zone can be effectively reduced. Therefore, the handling and selection of the OTDR launch box should be cautious. Using the launch fiber to overcome the OTDR dead zone is the option in most cases, especially for long fiber tests. Let the OTDR dead zone appear in the launch cable to ensure accurate test results. If the optical loss of the entire fiber cable is required, it is recommended to add launch fibers at the beginning and end of the fiber cable. If you need more specific information on OTDR launch boxes, don't hesitate to contact [email protected] for more details; we are happy to work for you.