This test is made to check that there is breathing resistance during warning.

Breathing resistance

1. Open the breathing circuit on the full-face mask or mouthpiece.

Wait until the warning is activated (if it is not already activated).

1. Lift the bellows slowly to position 3. Check that the bellows remain at position 3.
2. Breathe gently and check that there is breathing resistance during inhalation.
3. Repeat steps 2-4 twice to ensure that the breathing resistance warning is working and that it can only be sensed during the first inhalation phase.