How To: Avoid Common OTDR Test Problems

this chapter describes the procedure and common problems of the OTDR test tools and materials used for the test include the OTDR tester test fiber dust free paper and alcohol now let's introduce the preparations for the test clean the end surface of the test farmer use a piece of dust free paper dipped in alcohol to wipe the end of the connector two to three times connect the two test fibers using an adapter clean the end of the FC connector which is connected to the OTDR port test father connect OTDR the teeth of the test father connection OTDR connector should be aligned with the slot of the OTDR output port fasten the cables after they are properly installed click the OTDR mark on the testers display set parameters set the transmission distance pulse width and average duration for details about how to set parameters see the setting principles set the refractive index wavelength provided by the optical cable manufacturer select the wavelength again the tester machine used this time supports two wavelengths one three one zero in em and one five five zero in him and this time we choose one five five zero in him start the test find the serial number of the optical fiber to be tested on the ODF connect the OTDR to the optical port click on the OTDR tester to start the average luminescence after the test is completed save the information such as the optical Farmar start and end point Farber serial number and other information use the same method to test the remaining optical farmers edit and save the test results press the measurement icon on the top of the screen to move the a B cursor move a cursor to the straightest starting point of the fiber under test in the curve move B cursor to the end of the line segment to the left of the end reflection peak the attenuation per kilometer is displayed in the lower right corner of the screen the following is an analysis of the abnormal curve 1 the curve hazard began this may be caused by the farmer being squeezed at the big step or it is because of the optical fiber coil is too small or the fusion splicing quality is poor to the big angle may be caused by poor farmer quality and high attenuation or the optical cable is 2 times the optical cable fiber is not long enough 3 no reflection peak at the far end of the optical fiber the possible cause is that the fiber may be broken or the end is not cleaned or it's damaged a phantom or ghost appears on the curve because the measured optical fiber is short or there are multiple mechanical connectors on the link and they are close to each other the method for dealing with this problem is to decrease the optical power or increase their tenure Asian at the end 5 positive gain occurs in the optical fiber after the splicing point is larger than the optical fiber before the splicing point generating more back scattering scattered lights it is often found at the fusion splicing points of the fibers with different mode field diameter or back scattering coefficients actually the splicing point has loss generally the value is obtained using the bi-directional average method 6 the slope of the normal curve is smaller and uniform the curve is straight no abnormality exists the splicing point is not large and the step has no reflection peak common errors in the OTDR test one the test fiber ends connected to the OTDR are not cleaned with dust free paper dipped in alcohol to the teeth of the test fiber connector are not aligned with the slots of the OTDR light-emitting port three the connector of the test fiber is not tightened after being installed on the OTDR light-emitting port for the test fiber is not fully connected to the excessive barber and there is a gap between them fine the test fiber may be damaged six there's dust in the live connection these seven no oil is placed in the B of the live connection eight the end of the live connections are defective and irregular

Channel: Huawei

Views: 76,480

Keywords: Huawei, Huawei Technologies, 5g, mobile, Ren Zhengfei

Id: A4o38W8-ByI

Length: 6min 45sec (405 seconds)

Published: Mon Apr 27 2020