Spectroradiometers for UV, VIS and NIR: actinic flux, irradiance, direct sun, sky


CCD spectrograph with 2π optical head

The spectrographs cover the spectral range from the UVB to the near IR. They can be equipped with either irradiance or actinic receptor optics. A direct solar beam and a sky irradiance optics is also available. All instruments are installed in air- and water-tight housings. The instruments are deli­vered ready to use for the direct application in the atmosphere or in research aircrafts. The instru­ments are absolutely calibrated, a PC-programs to sample spectral data and to deduce calibrated spectra is included. The receptor optics is optimized for the spectral range of the instrument. The optics can be coupled directly or via optical fiber to the spectrograph. The fiber-optics connection is air and water tight as well.

A new ultra fast spectrograph uses a CCD-detector. The sensitivity of the back-thinned CCD is at least by a factor of 100 higher compared to the PDA device. Thus scan times of below 100 ms for the whole spectrum from 285 to ca. 650 nm are possible. This makes this instrument especially suitable for aircraft applications. The CCD is temperature controlled at 5 °C. The systems are control­led by a PC104 computer or via USB by a PC/notebook.


PDA-spectrographs: nominal spectral ranges:

230 – 1000 nm, resolution (FWHM) 3 nm optimized for the visible.

280 – 700 nm, resolution (FWHM) 2.1 nm, UV-optimized

280 – 700 nm, resolution (FWHM) 2.3 nm optimized in the visible.

Typical integration times for a full spectrum:

UVB: 3 000 ms, > 325 nm: 100 – 500 ms


250 – 980 nm, resolution (FWHM) 3 nm

280 – 700 nm, resolution (FWHM)<1.8 nm

Typical integration times for a full spectrum:

UVB: 100 ms, UVA/VIS: 20 – 100 ms

NIR spectrographs, InGaAs-detector:

900 – 1700 nm resolution (FWHM) 18 nm

and up to 2500 nm

900 – 1700 nm resolution (FWHM) 6 nm