Often, the longest dead zone occurs at the first connection (the OTDR bulkhead connector). Because it is impossible to measure loss within a dead zone, loss due to splices and connectors close to the OTDR launch point cannot be determined under ordinary circumstances. However, you can work around this problem by connecting the pulse suppressor box between the OTDR and the fiber under test. The length of fiber in the PSB distances the dead zone from the splices and connectors to be checked, and these crucial loss values can then be measured. With the modular PSB, a patchcord is required to connect the OTDR to the FTB-PSB. The fiber under test can be directly connected to the pulse suppressor box. Loss from the last connector of the fiber under test can be measured in the same way, by placing the extra fiber length of the PSB after the last connector. This extra fiber enables the OTDR to compare backscatter levels before and after the event to calculate the connector loss.
