Research on UV radiation measurements and correction methods

Abstract

The widely use of UV radiation led to the demand for improved understanding of the properties of instrumentation used to measure this radiation. The UV radiometers are mainly influenced by the factors as operating conditions, environmental conditions and the UV sources to be calibrated and measured. In addition, large errors can occur due to out-of-band, non-linear, and non-ideal cosine or spatial response of the UV meters. Through a new designed measurement system for cosine response property, we do some measuring experiments to 21 kinds of UV radiometers and calculate the relative deviation of each UV meters. The cosine errors are existed universally. It is recommended that keeping the UV source closing to a point source and perpendicular to UV detector when it is measured is very important. We also design and fulfill an experimental system to reflect the measuring errors of UV radiometers when measuring sources and calibrated sources are mismatched. The results show that if the measurement is of a broadband source, it is wise to unify the measuring and calibrated source or the two sources have similar spectral distribution. If that is not possible, we can calculate the spectral mismatch correction factor and spectral matching characteristic factor to correct the measuring data. All the works above are to let the users in appropriate usage of UV Radiometers in a standardized and comparable way and make the measurement quantities more accurate.