Kipp&Zonen UVS-E-T UV Radiometers - Manual (Page 5)

5
1. GENERAL INFORMATION
1.1 INTRODUCTION
The radiometers of the UVS Series (UVS-A-T, UVS-B-
T, UVS-E-T, UV-S-AB-T and UVS-AE-T) are designed
for precise measurements of atmospheric ultraviolet
radiation in three different spectral ranges. All models
measure global UV radiation, i.e. the sum of direct
solar radiation and the radiation which has been
scattered by particles or molecules in the air. The
angular response follows the cosine of the zenith angle
as with an ideal Lambertian surface.
The internal filter optics, detector and electronic
preamplifier of the UVS Series are thermo-electrically
controlled at a temperature of +25°C, independent of
the external temperature. This eliminates variations of
the spectral sensitivity caused by changing ambient
temperatures. In order to allow monitoring of the
internal temperature, an analog voltage output is avai-
lable, generated by an independent control circuit.
The spectral sensitivity of the UVS-E-T corresponds to
that of the human skin with regard to the Erythemal
Action Spectrum ISO 17166:1999 / CIE S 007/E-1998.
This is the response required by the United Nations,
World Health Organisation and World Meteorological
Organisation for measurement of radiation according to
the Global Solar UV Index (UVI). The analog output
voltage is a direct measure of the erythemally active
UV irradiance in W/m
2
. This irradiance can also be
expressed in UV Index by multiplying with the constant
40 m
2
/W.
The UVS-A-T and UVS-B-T radiometers allow precise
measurements of atmospheric UV-A and UV-B
irradiance. The analog output voltage is proportional to
the irradiances in W/m
2
.