General:
A measured volume of fuel is heated under controlled conditions at an elevated temperature for a specified period.
Precision:
The method includes established repeatability and reproducibility values based on interlaboratory studies. Precision depends on careful control of the test conditions, including temperature, test duration, fuel handling, and the evaluation of deposit formation.
Test:
After the test, the amount of insoluble material or deposits formed is determined by filtration and visual examination.
The results indicate the thermal stability of the fuel and its resistance to deposit formation during high-temperature operation.

