Photometer
device · 1760 · Industrial Revolution
A light meter.
What it is made of
- Paper screen with grease spot — has part. The spot vanishes when both sides are equally lit.
- Photometer bench scale — has part. The distance to the sources.
Principles and materials it uses
- Paper — is made of. A photometer compares the illumination of paper screens.
- Reflection of light — uses. Brightness is judged from reflected light.
What it is a kind of
- Sensor — is a kind of. A light sensor.
- Exposure meter — includes. A photometer.