Magneton scanner

A magneton scanner was a 24th century engineering tool that is one of the most thorough scanning devices aboard Federation starships.

In 2371, Harry Kim and B'Elanna Torres used a magneton scan to examine subspace fractures which were present on a planet in the Delta Quadrant as a result of a massive polaric ion explosion. The scan results indicated that, unlike most shock waves which dissipate into the future, the shock wave from the polaric ion explosion dissipated into the past, creating subspace fractures which could allow for time travel. The timeline in which these events took place was later negated when Captain Janeway managed to change history by ensuring that the explosion never took place. 

Later in 2371, the Voyager crew tried to scan for a non-corporeal alien lifeform moving from one crewman to another using a magneton scanner, as Paris suggested it was the most thorough scanning device aboard, but it was unsuccessful. 

Later that year, Torres suggested to Chell that a magneton scanner would degauss the transporter room in about five minutes; a lot faster than the micro-resonator he was using, but Tuvok told him it would teach him "patience". 

In 2373, when Captain Janeway was near death, she hallucinated that Torres used a Magneton scanner to search for her remaining presence aboard the ship, if there was anyway to help her. But this later turned to be an alien-induced near-death-experience.