During a routine inspection of a fiber optic network that services a critical communications infrastructure, you discover that some sections of the network are experiencing higher than normal signal attenuation. You need to quickly identify whether the issue is due to dirty connectors or actual damage to the fiber.

Which tool would be most effective for initially diagnosing the problem?

Fusion Splicer

spectrum Analyzer

Visual Fault Locator $($VFL$)$

Cable Certifier