You searched for: “sensitometers
sensitometer (s) (noun), sensitometers (pl)
1. A calibrated device with an optical light source that puts a set of densities on radiographic film: A sensitometer is used in quality control monitoring of film processors.
2. A measuring instrument that is used to determine the degree of responsiveness to a stimulus, such as the reactions to various amounts of light: The ophthalmologist used a sensitometer during her examination of Mr. Kaspar's ability to see so she could measure the reactions of the pupils of his eyes to light.