Which of the following types of test equipment requires periodic and traceable calibration?

An optical power meter is critical for measuring the power levels of optical signals in fiber optic cables. For accurate readings and reliable performance, it must undergo periodic calibration against established standards to ensure that the measurements reflect true signal conditions. This calibration process is essential because it addresses any drifts or inaccuracies that may develop over time due to temperature changes, component wear, or other environmental factors.

In contrast, while other test equipment like OTDRs, fiber identifiers, and inspection scopes can also benefit from calibrations, they do not always require the same level of traceability or regular calibration protocols as optical power meters. The optical power meter's reliance on precise measurements to ensure network performance makes its calibration particularly vital in maintaining the integrity of fiber optic installations.