A typometer is a ruler divided in typographic points or ciceros on one of its sides and in centimeters or millimeters on the other. Traditionally we used in the graphic arts to inspect the measures of typographic materials.
Although in DTP due to the technological advancements and greater precision we were using them less after 2000. Today I think they almost disappeared from most graphic design related professions.
This is now just a sweet memory.
printed on film
(in service 1990-2003)