To test whether your device pressure is responding as programmed, first be sure the Ramp Feature is not set.  To be certain, look at your Stand-by screen (0.0) and if there is nothing above the word "Pressure", there is no Ramp set on the device.  

Connect the tube adapter and the hose to your device.  

Press the on/off button to activate the blower.

When the blower is engaged, place your hand over the end of the hose to prevent air from escaping.

Watch the display screen.  You should see the pressure slowly increase, hesitate and then continue to increase, as if the unit is determining if you are having a apneic event.