What is the maximum allowable fiber loss?

Generally speaking, optical terminal equipment can be turned on in the range of -40DB, such as optical terminal, PDH, ONU, etc. However, in order to achieve a stable effect, it is suggested that the optical loss should not be greater than -25DB, which is the critical value for the normal and stable operation of optical terminal equipment. If the light loss is great, please clean the pig's tail with alcohol. If there is a flange connection, please check whether the flange connection is loose and whether the tail fiber is bent. Ensure that the loss value in the fused optical fiber does not exceed the standard (usually not more than 0.08DB). If the loss is still too large after confirmation, it is suggested to use OTDR test to find out the detailed part of the optical loss and make detailed treatment.