UPC connectors are usually blue, while APC connectors are usually green. Installing a connector on a fiber optic end face inevitably results in return loss, if the optical sinal loss is severe, it will seriously affect the reliability and stability of fiber optic transmission. In order to ensure better. As usual, the answer is, “It depends. UPC connectors are not exactly flat. The connector to the power meter generally doesn't matter as the female connector just holds the male Connector and points it at a sensor underneath, it doesn't actually mate with another connector within the power meter. This is why you aren't seeing any unexpected loss. What are the differences between APC, UPC, PC? How to distinguish them? How to choose between them? This post will tell. Based on the convex face properties of the PC, the connector utilizes an extended polishing method to create a better surface finish on the fiber.
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