Abstract: A method for automatically expanding and displaying a narrow pulse on an oscilloscope screen. The time sweep signal of the oscilloscope is first set to contain a predetermined number of input signal cycles. The speed of the time sweep is increased by an internal controller a number of settings to expand the signal cycle by a factor sufficient to place less than a single signal cycle within the sweep signal and an expanded singal pulse of greater than a specified duty factor outside the sweep signal. The dual trigger generators of the scope are set to trigger on opposite slopes of the pulse. If both trigger generators trigger, then the pulse is within the specified duty factor and the controller directs it to be displayed on the oscilloscope screen in its expanded form. The specified duty factor can be made exact by adjusting the duration of the sweep signal to match the duration of the duty factor once the period of the signal cycle is determined.