The point is there are a lot of variables and it is very possible that one ventilator will achieve better results that another. The only thing you could do in this case would be to recalibrate the unit. We do not publish an accuracy specification, only a repeatability specification. That is we state that in pressure mode, the Inspiratory pressure will not vary by more than 2 cmH2O once a pressure is established. As an example if set pressure is 30cmH2O, actual delivered pressure may be 26 but during that case the pressure will remain between 24 and 28.