An optical fiber cable run has been installed between two buildings, with a splice point in the middle linking a third building. It is now time to certify the link with a light source and power meter. The test equipment is set up to test at 850 nanometers. The source is connected to fiber 1 at the main crossconnect and the power meter at the intermediate crossconnect. The loss measured for this fiber span is 4.0 decibels. Is this attenuation acceptable?
The past few years have witnessed the boom in optical fiber being used in network communication industry. In order to make sure that the fiber network is reliable and accessible, a more accurate and faster methodology for assessing the integrity of the infrastructure is indispensable. Therefore, it is essential to choose the right fiber optic testing tool/device: not only to meet the enhanced testing requirements, but also help to increase the reliability and value of the whole network. OTDR is one of the most powerful test instruments for fiber cable testing.
As we all know, OTDR is an optical fiber test instrument, which can be used for attenuation measurement of optical fiber links, quality inspection of optical fiber connectors and optical fiber splices. It can not only measure the fiber length, but also analyze the loss distribution of the link. However, the quality of the existing OTDRs on the market is uneven, and there are various bugs.
- Single function, poor applicability and practicability in complex construction environment
- The UI interface experience is poor, and the human-computer interaction s
First of all, what is a curve? just look at the picture!
The red box in the figure above is a common curve chart in daily life.
How is the graph formed?
After the OTDR emits the test light, the circuit diagram is constructed through the principle of back-to-back Rayleigh scattering and Fresnel reflection.
The uneven deposits and impurities distributed along the fiber core scatter the test light back to the OTDR through the principle of scattering.
The basic principle of OTDR fiber tester is to measure the transmission loss caused by scattering, absorption, etc. and the structural loss caused by various structural defects by analyzing the backscattered light or forward scattered light in the fiber. When a certain point of the fiber is subjected to temperature or when the stress acts, the scattering characteristics of the point will change. Therefore, the disturbance information of the external signal distributed on the sensing fiber is detected by the correspondence between the display loss and the length of the fiber. How to read OTDR test curves?
Generally, it is a normal graph, A is a blind zone, and B is a test end reflection peak. The test curv
1.Basic principles of OTDR
The OTDR is called an Optical Time Domain Reflectometer, and a narrow optical pulse is injected into the end face of the fiber as a detection signal. When the light pulse propagates along the fiber, the backscattered portion of the Rayleigh scattering will continuously return to the incident end of the fiber. When the optical signal encounters a crack, a Fresnel reflection will occur, and the back-reflected light will also return. The entrance end of the fiber.
Rayleigh backscattering and Fresnel reflection occur when light propagates through an optical fiber. The OTDR utilizes the characteristics of light to collect backscattering and reflection of light pulses in the path. High-tech, high-precision photoelectric integrated instrument.
By detecting the size and arrival time of the back light at the input end by suitable photocoupler and high-speed response photodetector, the transmission characteristics, length and f
The Optical Time Domain Reflectometer (OTDR) is a vital tool for fiber optic testing. However, there is an unwanted phenomenon known as ‘dead zone’ that occurs when using an OTDR. This dead zone limitation can be avoided through the use of an OTDR Launch Box. OTDR Launch Cables are designed to be used in conjunction with an OTDR to measure complete link loss of a fiber.
The Launch Box Basics
The launch box, which is also known in the industry as a launch fiber, pulse suppressor, dead zone box or fiber ring, is a device that helps to eliminate the dead zone issue during fiber optic testing significantly. The dead zone is something that occurs when the pulse width changes and causes a high degree of reflection that can cover an area several hundred meters from where the OTDR is located. This results in the OTDR device not being able to detect events or issues in that area. Launch cables are offered in a variety of connector styles including SC, ST, LC, FC.
Optical Time Domain Reflectometry (OTDR) is an essential fiber testing tool. It can test optical losses and locate breaks, connectors and connectors in fiber optic networks. However, OTDRs have a “dead zone” and may affect test results if appropriate measures are not taken. To overcome the limitations of the OTDR dead zone, OTDR launch boxes are being used. This article will introduce the OTDR launch box for your reference.
Basic of OTDR Launch Box
The OTDR launch box has many other names, such as dead zone boxes, pulse suppressors, fiber optic rings, fiber optic launch cables, etc.
The dead zone of the OTDR is caused by high reflection levels and is affected by the pulse width and may extend hundreds of meters from the OTDR. It is recommended to use a full-length fiber before the fiber under test. Therefore, the OTDR receiver c
1. Use of OTDR
Fiber optic measurements with OTDR can be divided into three steps: parameter setting, data acquisition, and curve analysis.
Manually setting measurement parameters includes:
(1) Wavelength selection (λ):
Because different wavelengths correspond to different light characteristics (including attenuation, microbend, etc.), the test wavelength generally follows the principle corresponding to the transmission wavelength of the system transmission, that is, when the system is open at 1550 wavelength, the test wavelength is 1550 nm.
(2) Pulse Width:
The longer the pulse width, the larger the dynamic measurement range and the