|refractive index (n): Of a medium, the ratio of the velocity of propagation of an electromagnetic wave in vacuum to its velocity in the medium. |
The index of refraction is the ratio of the speed of light in a vacuum to the speed of light in a fiber. The tester uses the index of refraction to determine fiber length. The unit of measure is n. The n values defined in the fiber types menu of the DTX CableAnalyzer are suitable for most applications. Minor differences between the tester's n and a fiber's actual n usually do not make enough difference in length to fail a fiber.
Increasing n decreases measured length. If you try to enter a value outside the valid range for n, the DTX CableAnalyzer shows N/A for the value. The valid range is 1.1 to 1.71 inclusive.