The Collaborative International Dictionary of English v.0.48:
Spherometer \Sphe*rom"e*ter\, n. [Sphere + -meter: cf. F. sph['e]rom[`e]tre.] (Physics) An instrument for measuring the curvature of spherical surface, as of lenses for telescope, etc. [1913 Webster]WordNet (r) 3.0 (2006):
spherometer n 1: a measuring instrument for measuring the curvature of a surface