Tips & Tricks

• Use the PO2 reading for negative&positive tests. Suck/blow a under/over pressure and close the mouthpiece. See the PO2 reading and follow how it stays stable. For a negative test the PO2 may first be 0.21. After sucking an under pressure the PO2 may show 0.18. If the reading stays the same or rises very slowly then there is no significant leaks.