Systems and methods of measuring dynamic signals for power distribution units. In one embodiment, a power distribution unit (PDU) includes an analog to digital converter (ADC) including a plurality of channels, each channel corresponding to a respective outlet of a plurality of outlets of the PDU. The PDU further includes a microprocessor coupled to the ADC and configured to measure a scale of a signal output from a first channel of the ADC, compare the scale of the signal to a sensitivity threshold, and select, for a first outlet corresponding to the first channel, a reference voltage of a plurality of reference voltages for input to the ADC based on a result of comparing. Various embodiments allow using an ADC to measure low level outlet currents of less than around 300 mA in addition to high level currents such as around 20 A.