A Device Under Test (DUT) or Unit Under Test (UUT) is an electronic DUT whose characteristic values are determined. This can be a two-pole or a four-pole, a passive or active component, a cable or an optical fiber, an analog or digital circuit, a wafer, a module, a printed circuit board or a device.
For larger units, the designation Unit Under Test (UUT) is used instead of Device Under Test (DUT). For measurement, the DUT is assigned the relevant parameters and its behavior with respect to the parameters is determined and documented. The parameters and characteristic values are determined to a certain extent by the DUT. For example, the characteristic values of a capacitor are measured as a function of frequency, those of a memory chip as a function of the clock rate.