An efficient solution for combustion processes is simultaneous using signals of oxygen and carbon monoxide concentration. Most common analyzers used for these purposes apply zirconia sensor technique for oxygen measurement and infrared in-situ technique for carbon monoxide measurement. Disadvantage of infrared in-situ technique is a problem with proper installation point for CO analyzer. The temperature there has to be lower than 370stC (above this temperature dust particles start to emit infrared waves which disturb the measurement). The other problem meet quite often is high dust concentration that disturbs proper operation of in-situ CO analyzers. Alternative way is to measure CO by an extractive method. This technique comes with long response time and locate measuring point in considerable distance from oxygen analyzer point. The research carried out for using integrated measuring systems CO+O2 up to now has not been succeeded. Analytics offers zirconia oxygen analyzers and carbon monoxide analyzers for both: in-situ and extractive techniques. Analytics also provides on-field test for boiler optimization.