Abstract
The Schottky constant plays a central role in modern theories of field electron emission, thermal electron emission, and ionic field evaporation, particularly since the 1970s reforms in the international system of measurement. However, it is not widely recognised as a useful universal constant. This Poster provides a brief "tutorial" introduction to the Schottky constant, primarily for those not familiar with it. It provides a definition, and proof of relevant equations. It indicates the main contexts in which the Schottky constant is used, and demonstrates that the Schottky constant is a "property of the world" that is represented by technically different physical quantities in different equation systems.