SENSITOMETERS

Noun

sensitometers

plural of sensitometer

Source: Wiktionary

SENSITOMETER

Sen`si*tom"e*ter, n. [See Sensitive; -meter.] (Photog.)

Definition: An instrument or apparatus for comparing and grading the sensitiveness of plates, films, etc., as a screen divided into squares of different shades or colors, from which a picture is made on the plate to be tested.

Source: Webster’s Unabridged Dictionary 1913 Edition