radiometer

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.

An instrument that detects electromagnetic radiation.

An old instrument for measuring angles; the cross-staff.

An instrument which serves to transform radiant energy into mechanical work.

An instrument for the detection and measurement of small amounts of radiant energy.

A forestaff.

An instrument designed for measuring the mechanical effect of radiant energy.

A device that measures radiant energy.

meter to detect and measure radiant energy (electromagnetic or acoustic)