Metrological requirements for measurements of circadian radiation

The article presents a definition of circadian radiation and its influence on human beings. Typical sources of this radiation have been discussed and compared. As the availability of devices designed for circadian radiation measurement is very limited, and their quality is rather poor, there is a need for the development of a new meter which would deliver precise data. The paper presents available methods of optical radiation measurement which can be used in a circadian radiation assessment. Advantages and disadvantages of presented methods have been discussed. A light path in typical measurement instruments has been analyzed, as well as the impact of each component on the final result (i.e. the influence of spatial correction, optical filters and detectors). Original results of authors’ research have been presented and the concept for decreasing the measurement error has been proposed