What is the primary purpose of a proof load test on a cable?

The primary purpose of a proof load test on a cable is to evaluate the cable's structural integrity. This testing process involves applying a specific load to the cable to assess its performance under stress. By doing this, you can determine if the cable can handle the expected load in operational conditions and identify any potential weaknesses or defects in the material. The proof load test ensures that the cable meets safety standards and is suitable for its intended application, which is crucial for preventing failures during use.

The other options, while they may relate to cable maintenance and assessment, do not accurately reflect the main objective of a proof load test. Measuring the length of the cable, determining its weight, or checking for corrosion are important aspects of cable evaluation but do not contribute to understanding how well the cable will perform under load.