Brief Introduction of cable cabling system parameters and tests

This article introduces the optical fiber cabling system. Many people may not know about the optical fiber cabling system yet. I believe you will have a rough understanding of the optical fiber cabling system after reading this article, I hope this article will teach you more things.

After the optical cable cabling system is installed, You need to test the link transmission characteristics. The main test items are the attenuation characteristics of the link, insertion loss of the connector, and return loss. Next we will give a brief introduction to the measurement of key physical parameters of the optical cable cabling system and the troubleshooting and maintenance of the network.

1. Key physical parameters of Optical Fiber Links

Attenuation:

1. attenuation reduces the optical power during optical fiber transmission.
2. Calculation of total attenuation of the optical fiber network: optical fiber LOSS (LOSS) refers to the ratio of Power out at the output end of the optical fiber to Power in at the time of transmitting to the optical fiber.
3. The loss is proportional to the length of the optical fiber. Therefore, the total attenuation not only indicates the loss of the optical fiber, but also reflects the length of the optical fiber.
4. optical fiber loss factor α): To reflect the attenuation characteristics of optical fiber, we introduce the concept of optical fiber loss factor.
5. Measure the attenuation:

Because the optical fiber is connected to the light source and the optical power timing will inevitably introduce additional losses. Therefore, in the field test, you must first set the testing reference point of the tester, that is, the zeroth setting ). There are several methods to test the reference point, mainly based on the link objects to choose these methods. In the optical fiber cabling system, because the length of the optical fiber is usually not long, therefore, the test method will pay more attention to connectors and test jumpers. The method is more important. For more information, see anheng's wiring testing technical article.

Return Loss:

Reflection loss, also known as return loss, refers to the number of decibels in the ratio of backward reflected light to input light at the optical fiber connection. The larger the return loss, the better the effect of reflected light on the optical source and system. To improve the return loss, try to convert the optical fiber end face into a spherical or oblique spherical surface as an effective method to improve the return loss.

Insertion loss:

Insertion loss refers to the number of bits in the ratio of the output optical power to the input optical power after the optical signal in the optical fiber passes through the active connector;
The smaller the insertion loss, the better;
The insertion loss measurement method is the same as the attenuation Measurement Method;

Ii. testing and measuring equipment for optical fiber networks

1. Optical Fiber identification device.

It is a very sensitive photoelectric detector. When you bend an optical fiber, some light emits from the core. The light will be detected by the optical fiber identification device. Based on the light, the technicians can identify a single fiber in a multi-core optical fiber cable or an interboard from other optical fiber cables. The Optical Fiber identification device can detect the state and direction of light without affecting the transmission. To make this work easier, the test signal is usually modulated into 270Hz, Hz or Hz at the sender end and injected into a specific optical fiber. Most Optical Fiber identifiers are used in single-mode optical fiber cable cabling systems with a working wavelength of 1310nm or 1550nm. The best optical fiber identifiers are the ability to use macro bending technology to identify optical fiber cables online and to test the transmission direction and power of optical fiber cables.

2. Fault tracker ).

This device is based on the visible light and red light of the laser diode. when the light is injected into the optical fiber, similar faults such as fiber breakage, connector failure, excessive bending, and poor fusion quality occur, the optical fiber fault can be visually located by transmitting the light to the optical fiber. The visible fault positioner is emitted in Continuous Wave CW) or pulse mode. The typical frequency is 1Hz or 2Hz, but it can also work in the kHz range. Generally, the output power is 0 dBm (1 Mw) or less, the working distance is 2 to 5 km, and all universal connectors are supported.

3. Optical Loss Test Equipment, also known as A multimeter or power meter ).

To measure the loss of a optical cable link, a calibrated stable light must be transmitted at one end and the output power should be read at the receiving end. The two devices constitute an optical loss tester. When the light source and power meter are combined into a set of instruments, they are often referred to as the optical loss tester or A multimeter ). When we measure the loss of a link, one person needs to operate and test the light source at the sending end, and the other person needs to use the power meter at the receiving end to measure the loss value in one direction.

In general, we need to measure the loss in two directions because there is a directed connection loss or because of the asymmetry of the optical fiber transmission loss ). In this case, technicians must exchange equipment and perform measurement in another direction. But what should they do when they are separated by dozens of floors or thousands of meters? Obviously, if both of them have a light source and an optical power meter, they can measure both sides at the same time, the current advanced optical cable cabling system testing kit for certification testing can achieve two-way dual-wavelength testing, such as Fluke's CertiFiber and DSP Cable Testing series FTA cable cabling system testing packages.

In short, to complete a measurement of optical loss, a calibrated light source and a standard optical power meter are indispensable. For more detailed technical information, see the related products in anheng's cabling Testing Instrument category.

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2. Brief Introduction to the development of optical fiber cabling systems
3. Briefly describe the application of engineering Cabling Technology
4. Describes how to design a network cabling system identifier
5. FAQs about data center Integrated Wiring