Final answer:
To measure the diameter of wire rope, the measurement should be taken across the outer wires using a caliper, as this determines the rope's current-carrying capacity.
Step-by-step explanation:
To measure the diameter of a wire rope, you should measure across the rope at its widest part, which includes the outer wires. The measurement is typically not taken from the core, strand, or inner wires, though these are important parts of the wire rope's composition. The diameter of the wire is crucial because it determines the current-carrying capacity of the wire, with a larger diameter indicating a greater capacity. Wires are often characterized by their gauge, which is inversely related to the diameter. When measuring the diameter, a caliper can be used to accurately measure the outer wires' diameter.