01/21/2026
When is 100 ppm CO not actually 100 ppm?๐ค
If youโre checking a gas appliance for safety or performance, excess oxygen in the flue gas can lead to deceptively low CO readings โ giving you a skewed sense of its safety and efficiency. Donโt be fooled!
Thatโs why the SENSIT G3 performs an air-free CO test (CF Test), meeting standards like ANSI Z21.10, Z21.47, and NCI guidelines, to give you the true CO reading โ the one that keeps you safe and compliant.
What is an air-free CO measurement?
โก๏ธ Itโs a calculated CO value that adjusts for excess oxygen, showing how efficiently your gas appliance is running
Where do you test for air-free CO?
โก๏ธ At the flue or exhaust outlet of gas appliances (water heaters, furnaces, or rooftop HVAC units) where post-combustion gases are vented
Why does it matter?
โก๏ธ Because air-free CO is the metric recognized in codes, inspections, and rebate programs โ it proves your appliance is safe, compliant, and operating efficiently