Problems of UV‐B radiation measurements in biological research. Critical remarks on current techniques and suggestions for improvements

Problems concerning solar UV‐B measurements for biological research are described from the physical point of view. It is shown that current instrumentation and the observing techniques need to be improved. For reliable measurements the spectrophotometric device must be equipped with a multichannel detector system counting single photon events. This technique allows accurate measurements at solar light levels below 300 nm and the use of the sun for instrumental calibrations.