honestly not easy. u could bottle air drive way away n have someone test it with a gas meter.but gas meter has to b syncronized in CLEAN air. why the dude blew up the town in cali few yrs back. he DIDNT pre-sycronize til he was in the gas. u could go up 35 to ok n buy a meter n test it. turn it on n sync it while there. also it wouldnt hurt to get a higher grade CO detector. if u read the package,most read way higher than what ppl should b exposed to. in other words u is sick b4 it beeps a alert.