Accurate furnace gas temperature measurement is essential for performance and reliability diagnosis in all types and size of boilers. Delayed combustion, off-centre fire ball in cornered fired boiler, etc.

O₂ and CO measurement at the furnace exit (at the entry of second pass) can really help in understanding the combustion conditions in the furnace. Most systems use conventional Zirconia probe at the APH inlet.

The pulverized-fuel balance, air fuel ratio and particle size spectrum are key parameters for the optimization of the combustion process for many large scale - fossil and biomass fired - boilers. These parameters directly influence factors such as ignition delay, combustion efficiency, LOI, emission levels as well as slagging and fouling.

One of the biggest performance challenges in a coal fired boiler is the frequently changing coal quality and characteristics. To optimize performance, one needs to frequently adjust the combustion parameters as the fuel characteristics changes.

Reliable FBC bed temperature measurement is a great challenge due to high erosion. Whereas, accurate assessment of bed temperature is absolutely essential for FBC boiler operation.

Due to the presence of stones, boulders and other hard impurities in the coal, the cast steel ring hammers commonly used in Coal crushers undergo premature wear as well as breakage (metal fracture). This not only increases the replacement cost of ring hammers but also leads to severe consequential damage of other allied parts like shaft, guide plates, and housing leading to long outages and break downs.

Accurate metal temperature measurement of SH/ RH tubes is another challenge area for correctly assessing creep life of the components. In most cases these temperatures are picked up from the header stubs in the penthouse which do not represent the actual metal temperature inside the furnace.

Tube thickness measurement is a regular monitoring activity for all solid fuel fired boiler, which takes considerable time and manpower during AOH with the conventional UT technique. Also, since this test requires surface preparation and application of a liquid couplant between the tube surface and probe, thickness measurement is limited to few localized area.

Chemical additives are available for both solid and liquid fuel with various advantages as claimed by their vendors. If it works as claimed, then it could provide a reasonable solution to fouling while using fuel with high slagging index.

There are repetitive boiler tube failures due to fly ash erosion due to high percentage of ash in the coal that is being fired.