Densitometer

Rarity: Common

The most frequent rarity: most Wikipedia articles become Commons.

Rarity follows how well known the article is: its views on the French and English Wikipedia over a year, and the number of languages it exists in.

At a glance

Class

Notion

Domain

Science and technology

In collections

1 player has it in their collection.

What Wikipedia says

A densitometer is a device that measures the degree of darkness (the optical density) of a photographic or semitransparent material or of a reflecting surface. The densitometer is basically a light source aimed at a photoelectric cell.

Excerpt from the Wikipedia article “Densitometer”, under the CC BY-SA 4.0 license. Read the article on Wikipedia

Image: Jürgen Heiland, Public domain, via Wikimedia Commons.