Dark Matter Particles (DMPs) do not interact with electromagnetic force, but do have momentum. A Dark Matter Monitor consists of a high energy EM field filled with sub-atomic particles capable of interacting with DMPs. When these detector particles interact with DMPs they gain in mass and energy. This increase in mass causes the amplitude of the EM field to shift, but unlike neutrinos, DMPs dimensionally shift after the collision causing the wave to shift again. The level of DMPs are generally constant, but large energy events: such as dimensional jump drives change the local levels of DMPs.
The Dark Matter Monitor: A 100 Piece of Sci-Fi Minutia
From the Citadel · by axlerowes