Electroscopes have been widely used in physics education for several reasons, such as their simplicity, sensitivity and visual appeal, showing macroscopic phenomena related to the microscopic world. Although they are capable of highly accurate measurements, the procedures involved in these measurements encounter some obstacles when performed with simpler devices. This article provides some ideas for the quantitative measurement of ionizing radiation from radioactive decay using the electroscope together with the Tracker software, providing reliable measurements with easier data acquisition procedures.