Rail voltages are getting smaller, and tolerances are decreasing. As a result, making accurate power rail measurements has become more difficult. In the past, any scope was able to measure ripple on historical 5V rails with 10% tolerance, since the 500 mV requirement was well above the noise level of the scope. Industry dynamics are driving both a decrease in rail voltage values as well as tighter tolerances across a wide range of rails. This guide describes 5 tips for making accurate power integrity measurements with oscilloscopes.