Radiometry

Measurement of electromagnetic radiation (esp. optical radiation)

Radiometry is a set of techniques for measuring electromagnetic radiation, including visible light. Radiometric techniques in optics characterize the distribution of the radiation's power in space, as opposed to photometric techniques, which characterize the light's interaction with the human eye. The fundamental difference between radiometry and photometry is that radiometry can cover the entire optical radiation spectrum, while photometry is limited to the visible spectrum.

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