The nature and origin of cosmic rays remains one of the greatest puzzles of modern astrophysics, after more than 50 years since their first registration. Several ground experiments have reported the rate registered at its height of operation. To continue with the study of cosmic rays, it is proposed obtain the rate at different heights in the Earth’s atmosphere, developing a small and portable ultraviolet radiation detector, consisting of a scintillation plastic, a PMT, and a fast DAQ system. In this work, I present the design and construction of the UV detector, the events and rate recorded in Pico de Orizaba national park, campus Autonomous University of Puebla-Mexico, at a height of 4200 meters above sea level approximately. The rate obtained will compared with the number of registered particles per second, provided by experiments operating at heights known.