Radiometer

A radiometer or roentgenometer is a device for measuring the radiant flux (power) of electromagnetic radiation. Generally, a radiometer is an infrared radiation detector or ultraviolet detector.

 Types 
 The name Radiometer is frequently used to refer to a Crookes radiometer ("light-mill"). This is an early device wherein a rotor  in a partial vacuum spins when exposed to light. 
 The Nichols radiometer is a newer and more sensitive radiometer than the Crookes type. It measures radiation pressure. It has two small mirrors suspended on a quartz fiber. 
 A microwave radiometer operates in the microwave wavelengths. The radiometer contains argon gas to enable it to rotate.
 The MEMS radiometer can operate on the same principles of Nichols or Crooke radiometers.  It can operate over a wide spectrum of wavelength and particle energy levels.  MEMS Radiometer United States Patent 7,495,199

 References 

Category:Electromagnetic radiation