A system and method that improves and automates the measurement of power generated by an electrosurgical generator. An active load device is coupled to the generator output and is configured to simulate the change in tissue characteristics, such as an impedance change, that occurs when such tissue undergoes electrosurgical treatment. The active load faithfully simulates the change in tissue characteristics caused by a particular mode of electrosurgical energy delivery, such as without limitation, changes caused in response to a cutting mode, a coagulation mode, a blending mode, a sealing mode, and the like. Tests are conducted in accordance with test profiles containing target impedance and power values of the test scenario. A plurality of profiles may be stored for testing under various simulated operating conditions.