US Patent 11193764 Two datum vial mounting system and method

An automatic process and structural features for accurately producing levels is provided. The process enables more rapid production of levels, less operator work or error, and the ability to quantify errors and tolerances in the manufacture of the level. Coupling a level datum plane formed on the endcaps of a vial with a level datum plane of a frame ensures accurate construction of a level that can be automated and toleranced. Ensuring that the level datum plane created at the endcaps remains parallel (or at some other predesigned angle) to the measuring surfaces of the level reduces labor to manufacture the level and ensures measurement accuracy.