What is the Dynamic Range of an OTDR?When certifying or troubleshooting optical fibers in a network using an OTDR, the Dynamic Range is a key parameter of the device that determines the maximum length of the fiber that is observed during a test trace. In more technical terms, it is the distance between the point of the initial backscatter and the noise floor at the end of the fiber under test. The dynamic range value is measured and expressed in decibels (dB) and is essentially an analysis of power levels. OTDRs offering a larger dynamic range value can test longer lengths of fiber compared to those offering a smaller dynamic range value. Therefore, equating a dynamic range value with a fiber distance value is important when evaluating or specifying an OTDR for testing fibers in a network.
Calculating Dynamic Range
At the most basic level, the calculation relationship for equating a dynamic range value to a fiber distance includes three components: