An object's affects a magnetic sensor's ability to detect it.

An object's "composition" affects a magnetic sensor's ability to detect it.

We can define composition of any object as the nature of the ingredients that are included in that object. So, composition affects a magnetic sensor's ability And intensity of the change is the one that affect a magnetic sensor’s ability to detect changes in a magnetic field .
The meaning of intensity is the nature of being extremely solid, concentrated or troublesome or how much something is troublesome or solid.

The duration of a photographic flash is related to an rc time constantly