What must be done before making field measurements for end-to-end attenuation?

What must be done before making field measurements for end-to-end attenuation?

• A. The power meter must be adjusted
• B. The light source and optical power meter must be referenced together
• C. Calibration must be checked only once
• D. The optical fibers must be cleaned

Answer: (B)

The correct step before making field measurements for end-to-end attenuation is to reference the light source and optical power meter together. This process, known as establishing a reference level, is crucial because it ensures that both the light source and the measuring device are in agreement about the baseline optical power level. By referencing them together, you can accurately measure any loss of light that occurs as the signal travels through the fiber, allowing for precise calculation of attenuation. This referencing process is typically done by connecting the light source to the optical power meter with a short, clean fiber patch cable that is of known quality. Any subsequent measurements of loss can then be compared against this reference level, ensuring that the results reflect the true performance of the fiber link rather than discrepancies between the instruments themselves. The other actions mentioned, such as adjusting the power meter, checking calibration, or cleaning the optical fibers, while important, relate to general preparation for fiber testing but do not specifically address the prerequisite for field measurements of end-to-end attenuation. Proper referencing directly supports the accuracy of the attenuation measurement, which is the main concern in this context.

The correct step before making field measurements for end-to-end attenuation is to reference the light source and optical power meter together. This process, known as establishing a reference level, is crucial because it ensures that both the light source and the measuring device are in agreement about the baseline optical power level. By referencing them together, you can accurately measure any loss of light that occurs as the signal travels through the fiber, allowing for precise calculation of attenuation.

This referencing process is typically done by connecting the light source to the optical power meter with a short, clean fiber patch cable that is of known quality. Any subsequent measurements of loss can then be compared against this reference level, ensuring that the results reflect the true performance of the fiber link rather than discrepancies between the instruments themselves.

The other actions mentioned, such as adjusting the power meter, checking calibration, or cleaning the optical fibers, while important, relate to general preparation for fiber testing but do not specifically address the prerequisite for field measurements of end-to-end attenuation. Proper referencing directly supports the accuracy of the attenuation measurement, which is the main concern in this context.