Heisenberg compensator
The Heisenberg compensator was a component of the transporter system. The compensator worked around the problems caused by the Heisenberg Uncertainty Principle, allowing the transporter sensors to compensate for their inability to determine both the position and momentum of the target particles to the same degree of accuracy. This ensured the matter stream remained coherent during transport, and no data was lost.

A scan of the Heisenberg compensators, to ensure they were performing within the specified parameters, could be performed by raising the transporter pad. () 

While trying to devise a way to transport holographic matter off the holodeck without it disintegrating instantly, the idea was put forth that decoupling the Heisenberg compensators might let the matter reform normally, although the suggestion was used as a stalling tactic against Professor , and the idea had never actually been tried before. ()

In 2371, Chief Miles O'Brien ordered a crewman to check the Heisenberg compensators of the . ()

Additional references 
 

cs:Heisenbergův kompenzátor
de:Heisenbergkompensator
fr:Compensateur d'Heisenberg
Transporter technology