Thaumometer (Thaumcraft 5)

The Thaumometer is an item added by Thaumcraft 5. Right-clicking it on blocks or entities will scan them for Research.

In the upper left corner of the user interface will show a bar measuring the amount of Aura in the area. Pressing F (per default) with the Thaumometer in hand will change the bar to show a particular aspect (or back to showing all aspects).