The work presents the development of a device able to detect and quantify ionizing radiations. The transduction principle proposed for the design of the detector consists on using the properties of the fluorescent screens able to respond to the incident radiation with a proportional brightness. Though the method is well-known, it proved necessary to optimize the design of the detectors in order to get a greater efficiency in the relationship radiation/brightness; to that purpose, different models were tried out, varying its geometry and the optoelectronic device. The resultant signal was processed and presented in a visualization system. It is important to highlight that the project is in development and the results we obtained are preliminary.