just did the test, my brother hit the bong, and blew out at least 55 ppm of carbon monoxide, the alarm went off saying to vacate the premises! i hit the aromed vaporizer at 156F (max setting) and blew out a big vapor clowd onto the tester and it maintained a 000 ppm reading never flinching.... but i should have known that would be the result sinse carbon monoxide is essentially partially burned gas,... but i just wanted to confirm that and do my own test...