An impedance profile of a commercial power grid and a tester power distribution system is developed in this paper. The profile is used to identify the measurable frequency range of the power supply transient signals generated by a chip. Several resistance-capacitance (RC) models of the power grid are analyzed to determine the impact of each capacitance type. The impedance profile of a C4-based production testing environment is then developed. The impedance profile of the combined probe card and the power grid RC models illustrates the range of frequencies that are measurable at the supply ports of the chip-under-test (CUT). The results suggest that it is possible to measure the important frequency components of a chip's power supply transients in a production test environment for use in fault detection and localization procedures.