Radiometric converters were technological components utilized aboard Federation starships in the 24th century, for the purpose of absorbing toxic theta radiation, produced as a byproduct of antimatter waste, and recycling the energy to power various ship systems, such as life support and replicators.

In 2375, B'Elanna Torres, chief engineer of the USS Voyager, described the principles of radiometric converters to Malon Controller Emck, along with those of the transkinetic chamber, as a way of demonstrating the elimination of antimatter waste. Emck, however, received the information less than warmly, as the elimination of toxic reactants would put him out of the waste-exporting business. (VOY: "Night")

According to the Star Trek Encyclopedia (4th ed., vol. 2, p. 201), the converters were components in the energy byproduct processing system.