What is the maximum permissible fiber loss value

Generally speaking, -40DB range of optical terminal equipment can be opened, such as optical transceivers, PDH, ONU, etc., but to achieve stable results, it is recommended that the optical loss can not be greater than -25DB, -25DB is the critical value of the normal and stable operation of optical terminal equipment, if you find that the loss of light is large, please use alcohol to clean the pigtail head, and if there is a flange connection, check the flange connection. If you find that the optical loss is large, please clean the pigtail head with alcohol, if there is a flange connection, please check the flange connection to see if it is loose, and also check whether the pigtail has been bent, to confirm that the loss value of the melted fiber is not excessive (under normal circumstances can not be greater than 0.08DB), if you confirm that the above is still too large a loss, it is recommended that you use the OTDR test to find out the details of the place of the optical loss, and then carry out a detailed treatment.