Radiometers (direct measurements)

SPECTRORADIOMETER

This instrument allows measurement of radiation doses as a function of the wavelength. It is used to measure the distribution of solar irradiance, which enables the measurement of irradiance for specific wavelengths in the ultra-violet spectrum and visible range.

Advantage:

  • The spectroradiometer provides a real-time spectrum of UV radiation received.

Disadvantages:

  • Duration of scanning time (up to several minutes),
  • Cumbersome,

No overall coverage of the entire territory (few spectroradiometers in each country).

A solar UV spectrum measured on the ground

A solar UV spectrum measured on the ground

BROADBAND RADIOMETER

(example: Robertson-Berger UV meter)

The phosphor transforms the short ultraviolet wavelengths into visible light.

Broadband radiometer

Source : Solar Light

Advantage:

  • Fast response time.

Disadvantages:

  • Fixed wavelength, UV predefined response curve (usually fitted to the curve of the erythema).
Spectral response of UVB YES pyranometer and erythema action spectrum

Spectral response of UVB YES pyranometer and erythema action spectrum