Ash fusion, also known as fusibility, is a test used to evaluate how the ash residue left over after coal combustion would react in a furnace or boiler. The softening and melting behavior of fuel ash is shown by ash fusion temperatures. Despite a poor track record of associating with slagging or fouling behavior, these temperatures are frequently referenced in boiler fuel specifications. The device meets the ASTM standard for measuring the temperatures of four distinct transitional stages of the Ash Cone between dry and fluid conditions that would occur as a result of heating.

Orbit offers Ash Fusion Analyzers for various applications like Coal ash, Coke ash, Biomass ash etc.,