Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Furnishings and Equipment (hierarchy name)
4. Measuring Devices (hierarchy name)
5. measuring devices (instruments)
6. [measuring devices for phenomena]
7. light measuring devices
8. light absorption measuring devices

Narrower term/s

• photographic densitometers

Anotations

Scope note:

Instruments that measure optical density of materials or objects by measuring the intensity of transmitted or reflected light; used, for example, in photography to measure the opacity of images or to determine film speed.