Transpsychograph-u-lator

From Tardis Wiki, the free Doctor Who reference

The Transpsychograph-u-lator was a strange device invented by the Twelfth Doctor.

Upon presenting it, Hattie Munroe thought it wasn't real and he had made it up, which technically, he had.

It was supposedly used to track residual psychic traces. All they found was seaweed. (COMIC: Beneath The Waves)