ra·di·om·e·ter (rāˌdē-ŏmˈĭ-tər)

1. A device that measures the intensity of radiant energy, consisting of a partially evacuated glass bulb containing lightweight vertical vanes, each blackened on one side, suspended radially about a central vertical axis to permit their revolution about the axis as a result of incident radiation.
2. An instrument that detects electromagnetic radiation.
3. A device for determining the penetrative power of x-rays.

Related Forms:

• raˌdi·omˈe·try (-trē) noun