This paper presents a comparative analysis between the voltage interruption effects (higher and shorter than one minute) in the value of Pst indicator given by the flicker meter instrument. The Colombian regulator has proposed a modification in the flicker meter to disregard the interruption effects, in this paper an analysis related to this topic is presented. In order to simulate the effect of voltage interruptions, a model of the flicker meter has been developed in Matlab according to the IEC 61000-4-15 standard. Random quantities of interruptions with random duration have been simulated in fixed time intervals to study their impact in Pst value