Flue Gas Analyzer checks oxygen and carbon monoxide.
Press Release Summary:

Original Press Release:
Portable Flue Gas Oxygen And CO Analyzer
PORTABLE FLUE GAS OXYGEN AND CO ANALYZER
The Nova Model 360 Portable Flue Gas Analyzers have been designed for accuracy, reliability, ease of use and ease of service. They use customer replaceable sensors, which respond quickly to the 02 and CO present in the flue gas sample. The sensors' life expectancy is 2-3 years.
The Model 360 is complete with a built-in sample pump, 12 feet of sample hose, filter/condensate trap, flowmeter, rechargeable 'gel cell' battery and LCD digital readouts.
The Nova Model 360T also indicates net stack temperature for doing fuel efficiency calculations. The temperature sensor is built into the sampling probe. Efficiency charts for each fuel are provided.