OTDR voltage test method

OTDR voltage test method is through a constant current power supply, submarine cable station to the potential difference between the fault point, by the ratio of the voltage and current can be obtained from the submarine cable station to the resistance between the point of failure, submarine cable station is obtained and the distance between the fault point L, i.e., the type of Uo for fault occurs on the submarine cable power supply equipment (PFE) of the output voltage (V);N is the number of Repeaters;UR for repeater pressure drop (V);M as the number of branches;The U.As the branch of pressure drop (V);I for submarine cable constant power supply current (A);R for the submarine cable resistance per unit length (Ω/km).

In be used actually, only will be known when the submarine cable system failure of voltage, current and resistance (including Repeaters and branch voltage can provide reference for equipment factory of the product technical parameters) generation type (l), can get the approximate distance submarine cable fault point.Due to (1) not considering the earth resistance value of fault point, and each fault point resistance are different, so the test method of testing there must be a larger error.