A method and assembly for calibrating the pneumatic performance range of a system for delivering pneumatic power to a trocar, which includes the steps of: supplying pneumatic power to a trocar to achieve a desired cavity pressure； measuring the pneumatic power and cavity pressure over a time period, as the system attempts to maintain the desired cavity pressure； calculating performance characteristics of the trocar based on the measured cavity pressure and pneumatic power values； and adjusting the pneumatic power supplied to the trocar based upon the performance characteristics of the trocar.
