Description

The UV region covers the wavelength ranges 100-280nm (UVC), 280-315nm (UVB) and 315-400nm (UVA). Almost all UVC, and approximately 90 % of UVB from the sun is absorbed by the Earth’s atmosphere. For many applications it is only necessary to monitor the ‘total UV’ irradiance, which represents the combined UVA and UVB components. UVA radiation at the Earth’s surface is normally 15-20 times greater than UVB. The CUV5 is designed to monitoring the total UVA and UVB radiation.

The Ultraviolet (UV) part of the solar spectrum has several beneficial or adverse effects for human biology, plus many natural and synthetic polymers may crack or disintegrate, if they are not UV-stable. UVA and UVB measurements are used to monitor and investigate the effects of solar UV radiation on plants and animals. In materials testing important issues are the ageing effects of outdoor UV exposure that cause degradation, such as brittleness and discolouration. Measurements are also carried out under controlled conditions in environmental test chambers using artificial UV light sources.

The CUV5 has a high quality glass dome with extended UV transmission and a specially shaped diffuser to provide excellent directional response. The waterproof connector has gold-plated contacts and can be fitted 10m, 25m or 50m of high quality signal cable. The detection system includes optical filters and a photodiode detector, which generates a voltage output linearly proportional to the UV intensity without the need for a power supply.

Specification

To improve the measurement accuracy of the CUV5 radiometers the CVF4 ventilation unit can be used. It can be used outdoors under all weather conditions and includes a built in heater to keep the air just above ambient temperature which helps disperse precipitation and melt frost, or even melt snow and ice in cold climates. The CVF4 has a tacho output that can be used to check the proper operation of the CVF4. The output signal is 5V and nominal output should be at 146Hz. Higher frequency would suggest the filter needs replaced, whilst lower frequency could highlight an issue with the ventilator.

CUV5 is not suitable for the measurement of specific parts of the UV spectrum such as UV-A, UV-B, UV-E / UV-Index. For measurement of these parameters we recommend the UVS Series.

Associated Research Paper

University of Botswana, Gaborone, Botswana – Ultraviolet Characteristics of a Silicon Inversion Layer for Applications in Radiometry