The Heisenberg compensator is an essential component of transporter technology to ensure the integrity of transported matter.
The compensator counteracts effects of the applied characteristics identified in Heisenberg's Uncertainty Principle. To accurately isolate matter prior to its entry into the transporter buffer, all particles must be located, their velocity observed, and tracked. The compensators allow this to happen. (TNG episodes: "Realm of Fear", "Ship in a Bottle", DS9 episode: "Past Tense, Part I")