Fluke: optical fiber test Q &

Question 1:

Why do I need to perform a two-way test on the optical fiber?

A: No two are exactly the same as the optical fiber. We must keep this in mind. The diameter of the skin from their core to the outside is different, and the ring and connectivity may be different. In addition, if the optical fiber is connected to a link composed of an access adapter, any of the above inconsistencies may cause attenuation. In addition, the attenuation of the optical fiber is very particular about the direction. We need to know that the attenuation from End1 to End2 may be different from End2 to End1.

For example, a link is composed of two optical fibers with different diameters.

Which direction should we use to determine the attenuation? If you know the transmission direction, you can use the attenuation in the same transmission direction to determine the attenuation of the link. However, the problem is that you do not know how to transmit optical fiber cables when they are installed in a building. In this case, you need to use the most conservative method to test, that is, test both directions. Use the worst attenuation parameter value to determine whether your link can pass the standard.

The installation standards recognize the directionality of tests on optical fibers and provide testing methods. You can splice multiple optical fibers into one Backbone link by using connectors or other methods. TIA/EIA-568-B.1 requires you to test the Backbone link at least once in one direction. In fact, it implies that two-way testing should be a good method ). Based on the same standards, you can test only one direction on a horizontal link consisting of only one optical fiber.

Question 2:

I am looking for instructions on correctly testing 2 48-wire optical fibers. Two segments will be connected together by jumper. One cable is about 300 feet long, and the other is about 2500 feet long. As I said, these two segments will be connected together by short jumpers. The last end is connected to the switch, and the other end is connected to the device.

I'm looking for how to set up my light Loss Test Device OLTS) from end to test this optical cable connected by jumper. How many Jumpers do I need to perform the test correctly?

A: The quantity of jumpers required depends on the reference method, the connector type of each line to be tested, and the connector type of the testing device. Let's take a look at the article "Optical Cable reference settings in English) in the fluke network knowledge base to answer your questions in detail.

Question 3:

Is there any optical cable that can be located in an external pipe by a testing instrument?

A: It is very difficult to locate cables hidden in underground pipelines, especially when cables or pipelines do not contain metallic materials. Tracking wires are usually installed in pipelines to facilitate future cable locating. If a metal substance exists, you can use a 3 M cable positioner manufactured by another manufacturer to find the cable path or depth.

Question 4:

Whether the fluke network has a optical cable tester capable of measuring the fault point length, such as a bad optical cable or a poorly installed connector.

A: Yes, OptiFiber Optical Fiber certified OTDR provided by fluke Network) analyzer can diagnose bad optical cables and high-loss connectors. Optical Time Domain Reflector OTDR) can test the performance of installed optical cables and file their documents for record filing. OTDR displays a graphical curve of an installed optical cable. You can set active pointers on the graphic curve to measure the cable length, distance from the event, and evaluate the power loss between any two points. In addition, OptiFiber can analyze the curve and explain it in the event table. The distance to the fault point and loss events, such as circuit breaking, welding, severe bending, and connectors, are displayed in the event table.

Question 5:

What is the OTDR event dead zone?

A: The Event dead-time indicator represents the shortest length of the optical cable that OTDR can detect. The shorter the dead zone, the shorter the cable length that can be detected. If the event dead zone is shorter than the optical cable length you are testing, you can use OTDR to test this link.

Question 6:

Why is the event dead zone very important when OTDR is used to test optical cables?

A: The optical fiber links in a building are usually very short. In addition, they usually contain very short jumpers. When testing optical cables in a building, you should use an OTDR tester with a short event dead zone.

For example, if the optical cable link you are testing contains a three-meter jumper, if your OTDR event dead-time indicator is 10 meters, the OTDR will only detect the start end of the Jumper, the end point cannot be detected. If the OTDR event dead zone is 2 meters, you can view both ends of the jumper at the same time. In this case, you can correctly measure the length of the patch cord installed in the link and file for record.

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