Systems, methods and apparatus for regulating ion energies and ion energy distributions along with calibrating a bias source and a plasma processing chamber are disclosed. An exemplary method includes applying a periodic voltage function to a load emulator, which emulates electrical characteristics of a plasma load and associated electronics such as an e-chuck. The load emulator can be measured for various electrical parameters and compared to expected parameters generated by the bias source. Differences between measured and expected values can be used to identify and correct faults and abnormalities in the bias supply, the chamber, or a power source used to ignite and sustain the plasma. Once the bias supply is calibrated, the chamber can be calibrated by measuring and calculating an effective capacitance comprising a series and parallel capacitance of the substrate support and optionally the substrate.