Invenost

The Ivenost is a device used for the detection of planar boundaries. It can detect strength and direction of thin boundaries between dimensions. This allows them to find places where there are thinnings between realms or that portals have been established. While a variety of natural or constructed phenomena can prevent detection, the Ivenost is critical for those who travel the planes.
  Several varieties of Ivenost exist. Pocket ones, vehicle ones, and building sized ones. Each tend to be used for different purposes.
 

Handheld Ivenost

These are most useful in finding existing permanent portals between worlds. While not as sensitive or versatile as the large varieties, they make up for it by being easy to use and portable. These are the most common variety. Usually they contain a needle and some color indicators which grow in brightness based on the proximity of a portal and color variation by type of energy. Some variants include aspects of a sextant and compass that allow for varieties of travel. They tend to be harder to use, so perfectionists and survivalists prefer them to be individual tools. Some have been made from rough stone and wood, though they tend to not last as long as the brass ones. A famous set of brass and emerald encrusted ivenost, compass, sextant, and astrolabe is in the archives of the New Minam empire.
 

Vehicle mounted Ivenost

These are capable of greater range and finding more than just the closest portals. They can also filter out more noise and find regional seepage effects that relate to gates or even draconic influences instead of just active or passive portals. Many migrant societies will have one or two of these devices to allow them the ability to find important locations and waypoints in travel.
 

Building Sized Ivenost

These large Ivenost are capable of tracking multiple gates and portals and their changes over time. They can also be tuned to detect portable pocket dimensions at range. While the most powerful as to what they can detect, with the greatest range, they are also the most difficult to use. Most of these also track the ebb and flow of ley lines and the proximity of planes to the material realm. They were often built by magical universities, militaries, and some dragons. It is believed the Matron Mysterium has one included in it's peoples palace.