Impressions from the International UV Filter Radiometer Comparison, 2017
The campaign started successfully before the scheduled start. Most radiometers arrived at Davos in time.
Around 70 Radiometers participate at the campaign. Thanks to the shipping departement for the registration of the boxes and our civilian servant for the help of unpacking all the boxes.
The absolute calibration factor of broadband radiometers is determined relative to either the reference spectroradiometer QASUME or QASUMEII.
Roof Platform of PMOD/WRC
For the absolute calibration synchronized measurements from the radiometers and the reference spectroradiometer are acquired using the sun as light source.
Optical Laboratory - Dark room
After sufficient recording of sun irradiance the instruments are taken to the darkroom.
Spectral Responsivity Setup (SRF)
The optical table of the SRF setup is shown in the picture below. The light of a 1000 W Xenon lamp is focused to the entrance slit of an Acton SP2500 double monochromator. The UV broadband radiometer is illuminated by monochromatic light in the wavelength range from 270 to 420 nm. A Silicon diode monitors the stability of the system.
Angular Responsivity Setup (ARF)
The measurement of the ARF is carried out on a 3 m long optical bench. The light source is again a 1000 W Xenon lamp. The collimated beam illuminates the radiometer mounted on a goniometer.