focometer

[ foh-kom-i-ter ]

noun

, Optics.

1. an instrument for measuring the focal length of a lens or other optical system.

focometer

/ fəʊˈkɒmɪtə /

noun

1. an instrument for measuring the focal length of a lens

Word History and Origins

Origin of focometer¹

First recorded in 1850–55; foc(us) + -o- + -meter