What does a "normal" gradient indicate in a fully charged system?

A "normal" gradient indicates that the brake system is functioning correctly in terms of pressure distribution. When the system is fully charged, a normal gradient means that the expected pressure levels are present throughout the brake pipe. This condition is essential for effective braking, as it demonstrates that the brake pipe pressure is consistent and adequate for maintaining the desired brake force on the entire length of the train.

In this context, the correct understanding of a normal gradient is crucial for ensuring that there are no significant drops in pressure that could affect the braking performance. The other options either misinterpret the function of the gradient or mistakenly suggest that there are issues present in the system, which is not the case when referring to a "normal" condition.