What is electrical tracking in relation to insulators?

Electrical tracking refers to the phenomenon where a conductive path forms across the surface of an insulating material, typically as a result of environmental conditions such as moisture, pollution, or other contaminants. This conductive path can occur when the insulating surface degrades over time, allowing electrical currents to bridge the gap and create a pathway for electrical flow.

This is particularly relevant in applications where insulators are exposed to harsh conditions that can lead to surface deterioration. Effective insulators should resist tracking to maintain their protective qualities and prevent failure in electrical systems. In contrast, the other options pertain to specific properties or characteristics of insulation, such as the ability to measure dielectric strength or types of materials, but they do not accurately capture the concept of tracking itself.