What must a technician reference when measuring end-to-end attenuation?

When measuring end-to-end attenuation, it is essential to reference both the light source and the optical power meter together. This is because the light source generates the optical signal that will be transmitted through the fiber, while the optical power meter measures the amount of light that has been received after traveling through the fiber. To accurately determine the attenuation, which is the reduction in signal strength as it travels through the fiber, the technician needs to compare the output from the light source with the input measured by the optical power meter. This comparison allows for the calculation of attenuation in decibels (dB) over the length of the fiber optic cable.

On the other hand, while fiber type and length, average temperature and humidity, or the calibration schedule may provide context or influence the measurement process in different situations, they do not directly address the fundamental requirement of measuring end-to-end attenuation. The accurate measurement must rely on the interplay between the light source and the optical power meter for reliable results.