Abstract: An ultraviolet radiation detection exposure system determines either ultraviolet flux or accumulated ultraviolet energy. A detector converts the ultraviolet radiation into voltage, and a voltage-to-frequency converter provides a corresponding frequency. If the system measures flux, a conversion subsystem converts the frequency to an associated ultraviolet flux in watts. If the sensor measures ultraviolet energy over a period of time, a counter counts at the frequency of the voltage-to-frequency converter thereby integrating the received ultraviolet energy at the detector. A reset button allows the user to reset the system, clearing the counter, prior to entering the sun for the day. A warning light, display, or buzzer indicates to the user of the system that her skin is in danger of receiving a sun burn. A plurality of fibers and/or lambertian half-spheres are used to provide substantially uniform solar acceptance. A solar cell can be used to power the apparatus, especially within a watch configuration.