How Does OTDR Measure Distance?
The OTDR light time domain reflector is one of the tools related to light work and is used to test whether the fiber is intact, so let's see how it measures the distance. The OTDR light time domain reflector calculates the distance by measuring the reflected round-trip time. At the time of measurement, it is important to use the speed of light in the precise fiber, and the speed of light in the fiber is given by refractive index. As we all know, in a vacuum, the speed of light is 300000 kilometers per second, and in glass, the speed of light is about 200000 kilometers per second.
In this way, if you want to measure the distance, the OTDR light time domain reflector can be calculated by the following formula.
Distance = (time) * (speed of light in vacuum)/(Optical fiber refractive index) The optical fiber refractive index in the above formula is provided by the fiber optic manufacturer, with different optical fibers, and its fiber refraction rate is different. So if you want to measure the exact distance, you must have the correct refractive index of the fiber.
