Dry, weigh and place samples into crucibles, then load crucibles evenly inside the muffle furnace to avoid overlapping for consistent heat distribution.

Slow low-temperature heating evaporates sample moisture to prevent splashing and material loss at high heat.

Heat to target temperature under air to oxidize organics, leaving inorganic ash for tests with accurate temperature control.

Cool crucibles fully in furnace, take out ash samples for weighing and compositional analysis.