This article presents the design and construction of a prototype to measure the quality indicators of the electric energy service, which has capacity to measure the discontinuity in the service based on a voltage presence sensor that generates logic states in its exit, so the algorithm designed in a high level C and implemented in the microcontroller PIC18F2550, can register the events occurred in a period of three months. The prototype is built mainly by a liquid crystal display, a microcontroller, an external memory and a real time clock. This