'Sensitometer' definitions:

Definition of 'sensitometer'

(from WordNet)
noun
A measuring instrument for measuring the light sensitivity of film over a range of exposures

Definition of 'Sensitometer'

From: GCIDE
  • Sensitometer \Sen`si*tom"e*ter\, n. [See Sensitive; -meter.] (Photog.) 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. [Webster 1913 Suppl.]