People are exposed to natural or artificial UV radiation in different ways; unintentionally or intentionally, at their workplace on their spare time. To quantify the amount of individual UV exposure, a personal dosimetry is necessary. In research, polysulphone film (PSF) dosimeters are the most frequently used personal UV dosimeters. We use calculated weighting factors in the measurement processing of polysulphone film dosimeters. The special weighting factor transforms the dosimeter reading from an equivalent UV dose to the biologically effective UV dose. The factor depends on the investigated problem (action spectrum of the photobiological effect and spectral distribution of the incident UV source), the calibration of PSF was carried out once by a monochromatic radiation (gamma = 295 nm). The equivalent dose readings are available from this calibration curve for any investigated question. A presented result of this method is the seasonal measurement of erythemally effective UV exposure by ambient solar radiation, and the individual exposure level in a "normal" person concerning UV exposure and also in groups with the risk of a lack of sunshine. Further applications are occupational measurements of the risk of health damage by UV radiation (with respect to the limit of the maximum permissible 8 h-exposure according to IRPA/INIRC-guidelines). We controlled the extent of UV exposure in workers in the area of arc welding workplaces. The biological weighting of PSF readings simplifies a routine use of PSF in personal UV monitoring to investigators without the expending special measurement technology (e.g. spectroradiometer).