The disclosed electrosurgical systems and methods accurately determine the power actually applied to a load by using equalizers to calibrate the power measurements. The electrosurgical systems include an electro surgical generator and an electrosurgical instrument coupled to the electrosurgical generator through an electrosurgical cable. The electro surgical generator includes an electrical
energy source,
voltage and current detectors, equalizers that estimate the
voltage and current applied to a load, and a power calculation unit that calculates estimated power based upon the estimated
voltage and current. The methods of calibrating an electro surgical generator involve applying a
resistive element across output terminals of the electrosurgical generator, applying a test
signal to the
resistive element, measuring the magnitude and
phase angle of voltage and current components of the test
signal within the electrosurgical generator, estimating the magnitude and
phase angle of the voltage and current at the
resistive element using equalizers, and determining
gain correction factors and
minimum phase angles for the equalizers.