Abstract: An apparatus designed for monitoring the administering of ultraviolet therapy, particularly for portable use such as at the beach, has a control system adapted to monitor the instantaneous intensity of the ultraviolet light received by a subject being treated, wherein the instantaneous intensity is integrated by means of a rechargeable electrochemical cell to measure the total ultraviolet energy per unit area received by the subject during a given time. The apparatus is so controlled that when the total energy received by the subject as measured by the apparatus reaches a predetermined preset value as determined by the discharged state of the electrochemical cell, a warning signal either visible or audible is given to the subject. In an improved embodiment an electronic means is used to subtract the energy measured at one wavelength from the energy measured at other wavelengths, thereby providing a low cost filter means for selecting the desired wavelength to be measured.

Abstract: A system designed for more safely administering natural or induced light radiation to the skin of a subject, and having a control system adapted to monitor the instantaneous intensity of the ultraviolet light received by a subject being treated, wherein the instantaneous intensity is integrated and converted to a digital pulse output. The pulse rate is proportional to the instantaneous intensity. The pulses are counted to accumulate the total ultraviolet energy per unit area received by the subject. The apparatus is so controlled that when the total energy received by the subject reaches a predetermined preset value, the subject or doctor is alerted or notified either audibly or visually, e.g., when an ultraviolet lamp source is employed the lamp or lamps may automatically be turned off.