What unit is typically measured while testing fiber optic cables?

When testing fiber optic cables, the measurement typically used is in decibels (dB). This unit is crucial because it measures the attenuation or loss of signal strength in the fiber optic system. During installation and maintenance of fiber optic cables, understanding how much light is lost as it travels through the fiber is important in ensuring the system operates effectively.

Attenuation is a key factor in assessing the performance of fiber optic links, and it is expressed in decibels to indicate how much signal power is lost per unit length of the cable. A lower dB value indicates better performance, as less signal is being lost, which is essential for high-speed data transmission. By measuring the signal strength at varying points along the fiber cable, technicians can determine the overall health of the installation and identify any potential issues that could affect performance.

In contrast, the other units—volts, ohms, and watts—are more relevant to electrical characteristics in copper cables and electronic circuits rather than the light signal transmission characteristic of fiber optics. Thus, decibels remain the standard unit for assessing fiber optic cable performance, making it the most appropriate choice in this context.