When testing for fiber optic cable, there are two tools commonly used: OTDR & power meter. What might be surprising is that they can yield completely different results. While an optical power meter tests the received optical power, an optical time-domain reflectometer (OTDR) provides length and loss by utilizing backscatter reflection.
Why does that make such a difference? With a power meter, you’ll know if the fiber is cut or damaged along the way because you’ll note a level of wastage. With OTDR, you’ll know the distance to the break or if it made it to the test point desired. The downside is that if the level of wastage is needed, OTDR is not as accurate as a power meter. Another benefit of a power meter is that OTDRs can sometimes miss a source of signal loss, such as a fiber misalignment. You’ll also get different readings between an OTDR & power meter if there is a launch cable present.
Both an OTDR & power meter have their advantages and purposes, so most fiber optic companies will have both on hand when testing fiber optic cables. Some choose to use a power meter when a reliable, repeatable, and accurate test for overall loss is needed. OTDRs are excellent for finding faults and verifying splices and connections.
At GP Associates, Inc., headquartered in Knightdale, North Carolina, our experience in fiber optics slicing and testing puts us in the position of knowing which to use for a specific situation. We use both OTDR & power meter equipment to ensure that your fiber optic project is a huge success. Reach out to us today to learn more about our services.