The following points will lead to a large attenuation of optical fiber fusion:
1. The welding machine mode setting is incorrect, such as melting multi-mode or double cladding plus single mode welding;
2. There is a problem with the discharge capacitor, and the energy can't be reached during welding (this problem generally won't happen, otherwise the machine will be very bad);
3. Optical fiber mismatch, for example, you use single mode and multimode fusion;
4. Bad optical fiber cutting and uneven end face;
5. The optical fiber is not cleaned, and there is dust and air inside;
6. The quality of pigtail fiber is not up to standard, network level, telecom level and ordinary pigtail fiber. Generally, carrier-grade pigtails should be used for network speeds above gigabit;
7. coupler. The quality of coupler directly affects the loss value. According to my years of experience, the general loss value is too large, and most of the problems are reflected in the coupler;
8. The cable welder is not very skilled.