Clockwork Sensors are an array of extremly small magnetic diodes that pull on appropriate springs when powered by incoming electromagnetic radiation. This allows Clockwork to view the entire spectrum of light, but the distance at which they can see effectivly is limited, unless a special, expensive, configuration of the array is used. However, this is uncommon outside of planetary or ship-based sensory arrays.
This same technique can be applied to nearly every medium, including the spiritual realm, if materials that interact with them can be harvested by the Clockwork and are of sufficient purity to be machined into the array. It must be noted, however, that detectors for other mediums are rarely used by the Clockwork, who see no reason to waste the resources that are better spent elsewhere.